SA.45s芯片级原子钟
原子钟——精选推荐
原⼦钟利⽤原⼦的⼀定共振频率⽽制造的精确度⾮常⾼的计时仪器。
是世界上已知最准确的时间测量和频率标准，也是国际时间和频率转换的基准，⽤来控制电视⼴播和全球定位系统。
现在⽤在原⼦钟⾥的元素有氢、铯、铷等，最好的铯原⼦钟精度可以达到每500万年相差1秒。
现在的世界标准时间，即是由原⼦钟报时的协调世界时。
环球⽹：由于格林尼治标准时间跟不上计算机时代的发展，今后⼈们可能将以原⼦钟标准时间为准。
原⼦钟以原⼦共振频率标准来计算及保持时间的准确，是世界上已知最准确的时间测量和频率标准，也是国际时间和频率转换的基准，⽤来控制电视⼴播和全球定位系统卫星的讯号。
原⼦钟⾥的元素有氢、铯(sè)、铷(rú)等。
最好的铯原⼦钟精度可以达到每500万年相差1秒。
这为天⽂、航海、宇宙航⾏提供了强有⼒的保障。
[1]原⼦钟直到20世纪20年代，最精确的时钟还是依赖于钟摆的有规则摆动。
取代它们的更为精确的时钟是基于⽯英晶体有规则振动⽽制造的，这种时钟的误差每天不⼤于千分之⼀秒。
即使如此精确，但它仍不能满⾜科学家们研究爱因斯坦引⼒论的需要。
根据爱因斯坦的理论，在引⼒场内，空间和时间都会弯曲。
因此，在珠穆朗玛峰顶部的⼀个时钟，⽐海平⾯处完全相同的⼀个时钟平均每天快三千万分之⼀秒。
所以精确测定时间的唯⼀办法只能是通过原⼦本⾝的微⼩振动来控制计时钟。
[2]1945年，哥伦⽐亚⼤学物理教授Isidor Rabi建议采⽤他在⼆⼗世纪三⼗年代开发的原⼦束磁共振法制造时钟。
1949年，国家标准局（NBS，现称美国国家标准技术协会，简称NIST）宣告开发了全球第⼀台将氨分⼦⽤做振荡源的原⼦钟；1952年，该机构宣告开发了第⼀台将铯原⼦⽤做振荡源的原⼦钟，即NBS-1。
1955年，英国国家物理实验室制造出了第⼀台可⽤做振荡源的铯束原⼦钟。
在其后的⼗年中，越来越多的先进时钟相继问世。
1967年，第13届度量衡⼤会在铯原⼦振荡技术的基础上制定了SI秒，从此，全球的计时系统不再以天⽂学技术为基础。
芯片式原子钟
芯片式原子钟
芯片式原子钟是一种新型原子钟，利用原子的相干布局囚禁原理实现。
由于不再需要微波谐振腔，它可以做到真正的微型化，甚至物理部分可以比一粒米还要小。
这种原子钟被认为是能够集成到一个芯片上的原子尺度原子频率基准，因此也被称为芯片尺度原子钟（CSAC）或芯片级原子钟。
芯片式原子钟具有很高的频率精度，是航空航天、数字通信、网络授时、广播电视、铁路交通、电力传递等各系统中的时间频率基准。
它在国家战略领域，乃至整个国民生产生活中起着基础性的支撑作用。
此外，芯片原子钟是结合了集成电路制造的技术工艺方法，以相干布居数囚禁（CPT）原理为基础，研制出来的一种器件级别的微型化原子频率基准产品。
它是未来国内外时间频率领域研究的重要方向，无论是在军用还是民用领域，其应用范围都会十分广泛，可以在各种电子仪器设备中大规模替代晶体振荡器。
目前，这种芯片式原子钟的尺寸可以做得非常小，但仍能保证在较长时间内维持一个稳定的频率。
这得益于其内部精密的物理结构和先进的控制技术。
这种原子钟的稳定度已经达到了10的负10次方量级，这意味着在百万分之一小时内，其频率变化仅相当于一赫兹。
此外，这种原子钟的优点还包括低功耗、低维护成本和长的使用寿命。
由于其内部没有机械运动部件，因此也具有很好的抗震动和抗冲击性能，可以在各种恶劣环境中稳定工作。
总的来说，芯片式原子钟是一种具有广泛应用前景的高精度、高稳定性、低功耗、低成本的时间频率基准。
芯片原子钟
芯片原子钟原子钟是一种精确计时设备，它使用原子物理中的稳定振荡现象来测量时间。
芯片原子钟是一种小型化的原子钟，它将原子钟技术集成到芯片上，具有小巧、低功耗和高稳定性的特点。
下面将对芯片原子钟进行详细介绍。
芯片原子钟采用的基本原理是原子的振荡频率非常稳定。
在原子钟中，常用的振荡器是铯原子或针对铯原子进行调整的型号。
铯原子钟的原理如下：首先，铯原子被加热，使其蒸发成铯原子蒸气。
然后，这些原子通过激光束被囚禁在一个封闭的腔体内。
在腔体内，激光束与铯原子发生共振，使铯原子产生受激辐射。
之后，将受激辐射的频率通过一个稳定的振荡器转化为电信号，并进行计数和测量，从而得到非常准确的时间。
芯片原子钟是将原子钟的核心部分——振荡器集成到芯片上。
它的精确度通常在数纳秒到毫秒之间，比传统的石英晶体振荡器要高出几个数量级。
此外，芯片原子钟具有非常低的功耗，通常只需几十微瓦，可以极大地延长电池的寿命。
由于芯片原子钟的小型化和低功耗特性，它被广泛应用于移动设备、导航系统和数据中心等领域。
在移动设备中，芯片原子钟可以提供非常准确的时间信息，以便实现精确的定位和时间同步。
在导航系统中，芯片原子钟可以提供高精度的时间和位置信息，提高导航定位的准确性。
在数据中心中，芯片原子钟可以用于同步多台服务器的时间，保证数据的一致性和准确性。
然而，芯片原子钟也存在一些挑战和限制。
首先，腔体的封闭性和激光束的稳定性对芯片原子钟的精确度和稳定性有很大影响，需要采取一些措施来解决。
其次，芯片原子钟的制造和集成是一项技术难题，需要掌握核心的集成技术和原子物理知识。
最后，芯片原子钟的成本较高，需要一定的投资才能实现商业化应用。
总的来说，芯片原子钟是一种集成了原子钟技术的小型化设备，具有小巧、低功耗和高稳定性的特点。
它的应用范围广泛，可以提供准确的时间和位置信息。
虽然还存在一些挑战和限制，但随着技术的进步和成本的下降，芯片原子钟有望在更多的领域得到推广和应用。
铯原子钟调查报告
铯原子钟调查报告1.铯原子钟简介一种精密的计时器具。
日常生活中使用的时间精准到1分钟也就够了，但在近代的社会生产、科学研究和国防建设等部门，对时间的要求就高得多。
它们要求时间要准到千分之一秒，甚至百万分之一秒。
为了适应这些高精度的要求，人们制造出了一系列精密的计时器具，铯钟就是其中的一种。
铯钟又叫“铯原子钟”。
它利用铯原子内部的电子在两个能级间跳跃时辐射出来的电磁波作为标准，去控制校准电子振荡器，进而控制钟的走动。
这种钟的稳定程度很高，中国最新研制的铯原子喷泉钟NIM5，精度达到了连续走时1500万年，累积误差小于1秒【1】。
现在国际上，普遍采用铯原子钟的跃迁频率作为时间频率的标准，广泛使用在天文、大地测量和国防建设等各个领域中。
2.铯原子钟历史二十世纪30年代，美国哥伦比亚大学实验室的拉比和他的学生在研究原子及其原子核的基本性质时所获得的成果，使基于上述原子计时器的时钟研制取得了实质性进展。
二战后，美国国家标准局和英国国家物理实验室都宣布，要以原子共振研究为基础来确定原子时间的标准。
世界上第一个原子钟是由美国国家物理实验室的埃森和帕里合作建造完成的，当时这个钟需要一个房间的设备，另一名科学家扎卡来亚斯使得原子钟成为一个更为实用的仪器。
1954年，他与麻省的摩尔登公司一起建造了以他的便携式仪器为基础的商用原子钟。
两年后该公司生产出了第一个原子钟，并在四年内售出50个，如今用于GPS的铯原子钟都是这种原子钟的后代。
1967年，第十三届国际度量衡会议采用铯-133原子钟所发出特定波长的频率，作为秒的基准依据。
当此原子钟某特定波长所发出的光振动9,192,631,770 次所经过的时间，定义为一秒。
1995年在法国研制成功的冷原子钟（铯原子喷泉），利用了“激光冷却和囚禁原子原理和技术”，使原子钟的水平又提高了一个数量级。
目前，世界上只有法国、美国、中国、德国等少数几个国家研制成功。
今天，名为NIST F-1的原子钟是世界上最精确的铯原子钟，但它并不能直接显示钟点，它的任务是提供“秒”这个时间单位的准确计量。
cpt原子钟型号
CPT原子钟，即基于相干布局囚禁（Coherent（Population（Trapping）原理实现的原子钟，是一种芯片级原子钟。
CPT原子钟的型号包括但不限于以下几种：
1.SA.45S：由美国Symmetricom公司发布，整机功耗为115mW，体积为16cm³，频
率稳定度为2×10−10τ−1/2，启动时间为120s。
2.SA.53m/SA.55m：由Microchip公司发布，该系列原子钟充分借助CSAC和前代
SA.3Xm产品的CPT技术，是微型原子振荡器的新进展。
3.SYN010H：国产芯片级原子钟，采用国产元器件和工艺研制而成，工作温度范围-
40℃~+75℃，可在该温度范围内保证PPb量级的频率精度。
其外形及安装尺寸兼容SA.45s，具有低功耗、小尺寸、快启动的优点，可广泛应用于多种便携式设备及无人值守时频设备中。
这些原子钟型号各有其特点和优势，选择时需要根据具体的应用场景和需求进行考虑。
29.精品—国家综合定位导航授时体系PNT之体系发展的技术背景
12
技术背景——多种导航定位手段竞相发展
积极发展低轨增强星座，全方位提升卫星导航系统性能
Iridium
iGPS
STL
基于铱星低轨星座（66颗） 1616～1626.5 MHz下行频段 采用信息/信号增强方式 实现增强PNT服务
抗干扰：落地信号电平提升30dB 高精度：大幅缩短载波相位收敛时间 完好性：提供精度和完好性增强观测量和
2008.12 3GPP启动了 LTE（第四代移动 通信）系统中的定位标准化工 作，LTE 支持辅助定位技术。
15
技术背景——多种导航定位手段竞相发展
大力发展Micro-PNT等不依赖GPS的定位与制导技术
器件技术：已完成0.01°/h高精度MEMS陀螺样机，精度达到5×10-11、体积仅16cm3芯片级原子钟研制。
优 势
易用：可以软件或芯片形式嵌入手机等终端
廉价：消费类芯片成本仅十元
导航定位
广 武器精确制导
泛 监控、测控、搜救
应 用
通信、电力等时间基准
测绘、形变监测、地震预报
…
5
技术背景——导航定位授时（PNT）服务主要运营商
主要国家竞相发展卫星导航系统。
全球系统
区域系统
美国GPS
俄罗斯GLONASS 中国北斗
基本的GPS • 标准服务 (16-24m SEP)
–单频 (L1) –粗码捕获 (C/A) 码导航 • 精密服务 (16m SEP) –Y-码 (L1Y & L2Y) –Y-码导航
增强系统的能力
增加国防和民用的利益
Block IIR-M/ IIF (2005/2010年)
IIR-M: IIA/IIR 能力加上 • 笫二个民用信号 (L2C) • M-Code (L1M & L2M)
铯原子钟知识
铯原子钟所有时钟的构造都包括两大部分：能够按照固定周期走动的装置，如钟摆；还有一些计算、累加和显示时间流失的装置，如驱动时钟指针的齿轮。
大约50年前首次研制出的原子钟增加了第三部分，即以特定的频率对光和电磁辐射作出反应的原子，这些原子用来控制“钟摆”。
目前最高级的原子钟，就是利用106个液态金属铯原子对微波辐射产生共振效应来控制时针的走动。
这样的时针每秒约走动1011次，时钟指针走动得越快，时钟计算的时间也就越精确。
每一种原子都有自己的特征振动频率。
人们最熟悉的振动频率现象，就是当食盐被喷洒到火焰上时，食盐中的元素钠所发出的橘红色的光。
一个原子可以具有多种特征振动频率，可能位于无线电波波段、可见光波段，或介于其中。
铯－133则被普遍地选用作原子钟。
将铯原子共振子置于原子钟内，需要测量其中一种的跃迁频率。
通常是采用锁定晶体震荡器到铯原子的主要微波谐振来实现。
这一信号处于无线电的微波频谱范围内，并恰巧与广播卫星的发射频率相似，因此工程师们对制造这一频谱的仪器十分在行。
秒的定义随着精确测量时间的工具不断改进推出，人们自然会怀疑时间单位本身的精确性。
时间量测单位在数学方面定义的很清楚，一秒是1/60分钟，一分钟是1/60小时，亦即一小时是1/24天，一秒等于一天的1/86400。
但事实上，因为地球在运行之速度及距离太阳的改变，一个太阳日—由正午至正午的一段时间，并非都一样长。
公元1960年以前，CIPM （世界度量衡标准会议）以地球自转为基础，定义以平均太阳日之86400分之一作为秒定义。
即1秒＝1/86400平均太阳日。
然而地球自转并不稳定，会因其它星体引力的牵引而改变。
公元1960～1967年CIPM改以地球公转为基础，定义公元1900年为平均太阳年。
秒定义更改为：一秒为平均太阳年之31556925.9747分之一。
公元1967年举行的第十三届国际计量大会 (General Conference on Weights and Measures) 选择以铯原子的跃迁做为秒的新定义，即铯原子同位素Cs133基态超精细能阶跃迁9,192,631,770个周期所经历的时间，定为1秒（称作「原子秒」），秒的新定义使计时方式进入了原子的时代，此定义一直维持至今。
芯片原子钟 产品介绍 DS_SA45s_CSAC
Key Features• Power consumption <120 mW• Less than 17 cc volume, 1.6” x 1.39” x 0.45”• Aging <3.0E-10/month• 10 MHz CMOS-compatible output • 1 PPS output and 1 PPS input for synchronization • Hermetically sealed• RS-232 interface for monitoring and controlApplications• Underwater sensor systems • GPS receivers• Dismounted military radios • Anti-IED jamming systems • Autonomous sensor networks • Unmanned vehiclesWith an extremely low power consumption of <120 mW and a volume of <17 cc, the Symmetricom ® SA.45s Chip Scale Atomic Clock (CSAC) brings the accuracy and stability of an atomic clock to portable applications for the first time.The SA.45s provides 10 MHz and 1 PPS outputs at standard CMOS levels, with short-term stability (Allan Deviation) of 1.5E-10 @ 1 sec, long-term aging of 3E-10/month, and maximum frequency change of 5E-10 over an operating temperature range of -10°C to +70°C. The unit can also be ordered with a wider temperature range (Option 002) of -40°C to +85°C, with slightly higher power consumption and a wider maximum frequency change over temperature.SA.45s CSACChip Scale Atomic ClockThe SA.45s CSAC accepts a 1 PPS input that may be used to synchronize the unit’s 1 PPS output to an external reference clock with ±100 ns accuracy. The CSAC can also use the 1 PPS input to discipline its phase and frequency to within 1 ns and 1.0E-12, respectively.A standard CMOS-level RS-232 serial interface is built in to the SA.45s. This is used to control and calibrate the unit and also to provide a comprehensive set of status monitors. The interface is also used to set and read the CSAC’s internal time-of-day clock.DATA SHEETSymmetricom invented portable atomictimekeeping with QUANTUM™, the worldʼs first family of miniature and chip scale atomic clocks.Choose QUANTUM™ class for best-in-class stability, size, weight and power consumption.Low Power Consumption By Design Every part of the SA.45s CSAC has been engineered for low power consumption.It starts with the physics package, shown here in a cutaway view. A vertical-cavity surface-emitting laser (VCSEL) that has been highly optimized for this specific application illuminates the atomic vapor resonance cell, and the light that gets through the cell is then detected by the photodetector. The photodetector output signal drives a feedback loop which is used to achieve atomic resonance using the principles of coherent population trapping (CPT).The entire physics package has a volume of only 0.35 cm3, and the actual resonance cell itself has a volume of only 2 mm3. It is this extremely small size, plus the fact that it is surrounded by a vacuum within the physics package, that allows the entire physics package to be powered by about 15 mW. As the cutaway drawing shows, the only way the physics package connects with the outside world is through a top and bottom polyimide suspension. All signals that need to go to or from the center stack-up are carried on traces that are printed on the suspensions. And because the suspensions are connected to a frame that is engineered to be slightly shorter than the center stack-up, they are in tension and serveto hold the stack-up in place. The resultis a very small, highly thermally isolated, and robust physics package with excellent performance. All of the electronics that surround the physics package, and which turn it into a fully functional clock, have also been engineered for low power consumption. Even the CSAC controller’s firmware routines have been optimized for low power consumption.Low Power Is Just The BeginningAn atomic clock that consumes only 120mW of power (125 mW for option 002)instead of 10 W or more gives systemdesigners a new and important degree offreedom. But that is just the beginning.Because of its small size and high thermalisolation, the SA.45s CSAC warms up in<130 sec, compared to 8 minutes or morefor conventional atomic clocks. Also, powerconsumption during warm-up is only 140mW, while conventional atomic clocks willoften consume two times their steady-state power during warm-up. Finally, theCSAC’s power consumption variation vs.temperature is negligible, while otheratomic clocks can show variations of 200%or more across their specified temperaturerange.The World's Smallest Atomic ClockPower consumption and size are bothcritical to enabling portable applications,and the SA.45s is by far the smallestatomic clock available. For example, whilethe SA.45s CSAC does not quite equal theperformance of Symmetricom’s XPROrubidium oscillator, the figure shows ithas approximately 1/30th the volume—and1/14th the weight—of the XPRO. Conversely,the SA.45s has much higher performancethan OCXOs, and still offers a 4x reductionin volume compared to popular OCXOpackage sizes.SA.45s CSAC is1/30th the volumeof the XPROS A.45s C S A CX P R O030510152025The SA.45s CSAC is approximatelyUnderwater Sensor Systems Underwater sensors are used in seismic research, oil exploration and many other applications. Sensors designed to lie on the ocean floor will typically include a hydrophone, a geophone and a very stable clock to time-stamp the data collectedby the sensor. Because GPS signals can’t penetrate water, oven-controlled crystal oscillators (OCXO’s) have been used to provide the accuracy needed for most time-stamping applications.But the SA.45s CSAC is a nearly ideal clock for these underwater applications. Because it consumes 1/10th to 1/30th the power ofan OCXO, it requires much less battery power, resulting in smaller and lower-cost sensors, or alternatively, sensors with a much longer mission life.The SA.45s CSAC’s aging rate, which can be 1/100th of even a good OCXO, means that time-stamping errors caused by drift are greatly reduced. Finally, the SA.45s CSAC’s superior temperature coefficient means that when sensors are calibrated to GPS on a warm boat deck, but then dropped into cold ocean water of several hundred meters depth, the offset error produced by this temperature change is minimized.Portable Military SystemsMany advancements in military electronics are aimed at bringing the networked battlefield to the tactical edge, i.e. the individual warfighter. But there are limitations on how many pieces of gear and how much battery weight a warfighter can be expected to carry. This is especially true when operations are carried out in rugged terrain and/or high altitude. The CSAC’s small size, light weight, and extremely low power consumption can help in a number of systems: Dismounted IED Jammers: size and weight are always at a premium, so the SA.45s CSAC is an attractive option. Also, power not applied to the timing subsystem is power that can be applied to the jammer itself, or that can be used to extend mission life. The CSAC's precise synchronizationis critical to prevent self-jamming, whileits ultra-stable holdover is equally vital in GPS-denied environments.Dismounted Radio Systems: the SA.45s CSAC helps to minimize size, weight, and power consumption. At the same time,it provides the high accuracy required by many modern high-bandwidth waveforms, and it provides the stability needed to maintain network synchronization in GPS-denied environments.GPS Receivers: using the SA.45s CSAC as a timebase, military GPS receivers can achieve greatly reduced Time To Subsequent Fix (TTSF) for 24 hours or more. It also becomes possible to operate with only three satellites in view (instead of the usual 4), a distinct advantage in manyurban settings.Unmanned Aerial VehiclesAs the number of applications for civil and military umanned aerial vehicles (UAVs) rapidly expands, the suppliers of payloads for these vehicles are being pressured to increase their functionality. In doing so, they find themselves bumping into limitations in size, weight and power.The SA.45s CSAC can help in all threeareas, with a volume of <17 cm³, a weight of <35 g and power consumption of <125 mW. In fact, in some applications the CSAC is attractive solely because, when compared to conventional rubidium oscillators(~20 W in warm-up, ~10 W in steady state), its low power consumption simplifies thermal management issues.Many UAV’s rely on GPS, and the SA.45s CSAC can be disciplined by the 1 PPS output from a GPS receiver, and provide a stable signal that can be used by C4I or SIGINT payloads. And of course, should GPS be lost due to natural interference or jamming, the SA.45s CSAC provides a stable holdover signal that meets the requirements of even long-endurancemissions.1 Tune2 N/A3 N/A4 BITE5 Tx6 Rx7 Vcc8 GND 91 PPS IN 10 1 PPS OUT 11 N/A 1210 MHz OUTPIN NO. FUNCTIONMechanical InterfaceOptions to Meet a Wider Range of ApplicationsThe standard SA.45s CSAC (options 001 and 002) provides an output frequency of 10MHz. However, other frequencies are available: option 006 provides a 5 MHz output, option 003 provides 16.384 MHz, and option 004 provides 10.24 MHz. Other frequencies are also possible; contact Symmetricom for details.For applications where the very best Allan Deviation (ADEV) is not required, the SA.45s CSAC is also available with less stringent ADEV specifications at a lower price. For example, at TAU = 1sec, option 001 has an ADEV specification of 1.5E-10, while option 101 has a specification of 3E-10....................................................................................................................................................................ELECTRICAL SPECIFICATIONS-001 -002RF Outptut - Frequency: 10 MHz 10 MHz - Format: CMOS CMOS - Amplitude:0V to Vcc 0V to Vcc - Load impedance: 1 MΩ 1 MΩ- Quantity: 1 11 PPS Output- Rise/fall time (10%-90%)at load capacitance 10pF: <10 ns <10 ns - Pulse width: 400 µs 400 µs - Level:0V to Vcc 0V to Vcc - Logic High (V OH ) min: 2.80 V 2.80 V - Logic Low (V OL ) max: 0.30 V 0.30 V - Load impedance: 1 MΩ 1 MΩ- Quantity: 111 PPS Input - Format: Rising edge Rising edge - Low level: <0.5 V<0.5 V- High level:2.5 V to Vcc 2.5 V to Vcc - Input impedance: 1 MΩ 1 MΩ- Quantity:1 1Serial Communications - Protocol: RS232RS232- Format:CMOS 0V to Vcc CMOS 0V to Vcc - Tx/Rx impedance: 1 MΩ 1 MΩ- Baud rate:57600 57600Built-in Test Equipment (BITE) output - Format: CMOS 0V to Vcc CMOS 0V to Vcc - Load impedance: 1 MΩ 1 MΩ- Logic: 0 = Normal operation 0 = Normal operation 1 = Alarm 1 = Alarm Power Input - Operating: <120 mW <125 mW - Warmup:<140 mW <140 mW - Input voltage (Vcc):3.3 ± 0.1 VDC3.3 ± 0.1 VDCPHYSICAL SPECIFICATIONS- Size: 1.6” x 1.39” x 0.45” 1.6” x 1.39” x 0.45”- Weight: <35 g<35 g- MTBF:>100,000 hours>50,000 hoursENVIRONMENTAL SPECIFICATIONSOperating:- Operating temperature: -10°C to +70°C -40°C to +85°C- Maximum frequency change over operating temp range (max. rate of change 0.5 °C/minute): 5x10-10 1x10-9- Frequency change over allowable input voltage range: <4x10-10<4x10-10ENVIRONMENTAL SPECIFICATIONS (Continued)-001 -002- Magnetic sensitivity(≤2.0 Gauss):<9x10-11/Gauss <9x10-11/Gauss - Radiated emissions: Compliant to FCC Compliant to FCC part 15, Class B, part 15, Class B, when mounted when mounted properly onto properly ontohost PCB.host PCB.- Vibration: Maintains lock under Maintains lock under MIL-STD-810, MIL-STD-810, Method 514.5,Method 514.5,Procedure 1, 7.7 grms Procedure 1, 7.7 grms - Humidity: 0 to 95% RH per 0 to 95% RH per MIL-STD-810, MIL-STD-810,Method 507.4.Method 507.4Storage and Transport (non-operating):- Temperature: - 55°C to +90°C - 55°C to +90°C - Shock (1 ms half-sine): 1000 g 1000 g- Vibration: MIL-STD-810, MIL-STD-810, Method 514.5, Method 514.5,Procedure 1, 7.7 grmsProcedure 1, 7.7 grmsPERFORMANCE PARAMETERSStability (Allan Deviation) ADEVTAU = 1 sec 1.5x10-10 2x10-10TAU = 10 sec 5x10-11 7x10-11TAU = 100 sec 1.5x10-11 2x10-11TAU = 1000 sec5x10-127x10-12RF Output Phase Noise (SSB)1 Hz <-50 dBc/Hz <-50 dBc/Hz 10 Hz <-70 dBc/Hz <-70 dBc/Hz 100 Hz <-113 dBc/Hz <-113 dBc/Hz 1000 Hz <-128 dBc/Hz <-128 dBc/Hz 10000 Hz <-135 dBc/Hz <-135 dBc/Hz 100,000 Hz<-140 dBc/Hz <-140 dBc/HzFrequency Accuracy- Maximum offset at shipment: ±5x10-11 ±5x10-11- Maximum retrace (48 hrs off): ±5x10-11 ±5x10-11- A ging, monthly*: <3x10-10 <3x10-10- Aging, yearly*: <1x10-9 <1x10-9- 1 PPS Sync.: ±100 ns ±100 ns(*After 30 days of continuous operation)Digital Tuning - Range: ±2x10-8 ±2x10-8- Resolution: 1x10-12 1x10-12Analog Tuning - Range: ±2.2x10-8 ±2.2x10-8- Resolution: 1x10-111x10-11- Input: 0-2.5V into 100 kΩ 0-2.5V into 100 kΩWarm-up Time<130 s<180 sSolderHand solder using 63/37 Tin/Lead Solder with maximum soldering tip of 329°C (625°F)SpecificationsPart numbers 090-00218-001 and 090-00218-002All specifications at 25°C, Vcc =3.3VDC unless otherwise specified...................................................................................................................................................................ELECTRICAL SPECIFICATIONS-101 -102RF Outptut - Frequency: 10 MHz 10 MHz - Format: CMOS CMOS - Amplitude:0V to Vcc 0V to Vcc - Load impedance: 1 MΩ 1 MΩ- Quantity: 1 11 PPS Output- Rise/fall time (10%-90%)at load capacitance 10pF: <10 ns <10 ns - Pulse width: 400 µs 400 µs - Level:0V to Vcc 0V to Vcc - Logic High (V OH ) min: 2.80 V 2.80 V - Logic Low (V OL ) max: 0.30 V 0.30 V - Load impedance: 1 MΩ 1 MΩ- Quantity: 111 PPS Input - Format: Rising edge Rising edge - Low level: <0.5 V<0.5 V- High level:2.5 V to Vcc 2.5 V to Vcc - Input impedance: 1 MΩ 1 MΩ- Quantity:1 1Serial Communications - Protocol: RS232RS232- Format:CMOS 0V to Vcc CMOS 0V to Vcc - Tx/Rx impedance: 1 MΩ 1 MΩ- Baud rate:57600 57600Built-in Test Equipment (BITE) output - Format: CMOS 0V to Vcc CMOS 0V to Vcc - Load impedance: 1 MΩ 1 MΩ- Logic: 0 = Normal operation 0 = Normal operation 1 = Alarm 1 = AlarmPower Input - Operating: <120 mW <125 mW - Warmup:<140 mW <140 mW - Input voltage (Vcc):3.3 ± 0.1 VDC3.3 ± 0.1 VDCPHYSICAL SPECIFICATIONS- Size: 1.6” x 1.39” x 0.45” 1.6” x 1.39” x 0.45”- Weight: <35 g<35 g- MTBF:>100,000 hours>50,000 hoursENVIRONMENTAL SPECIFICATIONSOperating:- Operating temperature: -10°C to +70°C -40°C to +85°C- Maximum frequency change over operating temp range (max. rate of change 0.5 °C/minute): 5x10-10 1x10-9- Frequency change over allowable input voltage range: <4x10-10<4x10-10ENVIRONMENTAL SPECIFICATIONS (Continued)-101 -102- Magnetic sensitivity(≤2.0 Gauss):<9x10-11/Gauss <9x10-11/Gauss - Radiated emissions: Compliant to FCC Compliant to FCC part 15, Class B, part 15, Class B, when mounted when mounted properly onto properly ontohost PCB.host PCB.- Vibration: Maintains lock under Maintains lock under MIL-STD-810, MIL-STD-810, Method 514.5,Method 514.5,Procedure 1, 7.7 grms Procedure 1, 7.7 grms - Humidity: 0 to 95% RH per 0 to 95% RH per MIL-STD-810, MIL-STD-810,Method 507.4.Method 507.4Storage and Transport (non-operating):- Temperature: - 55°C to +90°C - 55°C to +90°C - Shock (1 ms half-sine): 1000 g 1000 g- Vibration: MIL-STD-810, MIL-STD-810, Method 514.5, Method 514.5,Procedure 1, 7.7 grmsProcedure 1, 7.7 grmsPERFORMANCE PARAMETERSStability (Allan Deviation)ADEVTAU = 1 sec 3x10-10 3x10-10TAU = 10 sec 9.5x10-11 9.5x10-11TAU = 100 sec 3x10-11 3x10-11TAU = 1000 sec9.5x10-129.5x10-12RF Output Phase Noise (SSB)1 Hz <-50 dBc/Hz <-50 dBc/Hz 10 Hz <-70 dBc/Hz <-70 dBc/Hz 100 Hz <-113 dBc/Hz <-113 dBc/Hz 1000 Hz <-128 dBc/Hz <-128 dBc/Hz 10000 Hz <-135 dBc/Hz <-135 dBc/Hz 100,000 Hz<-140 dBc/Hz <-140 dBc/HzFrequency Accuracy- Maximum offset at shipment: ±5x10-11 ±5x10-11- Maximum retrace (48 hrs off): ±5x10-11 ±5x10-11- A ging, monthly*: <3x10-10 <3x10-10- Aging, yearly*: <1x10-9 <1x10-9- 1 PPS Sync.: ±100 ns ±100 ns(*After 30 days of continuous operation)Digital Tuning - Range: ±2x10-8 ±2x10-8- Resolution: 1x10-12 1x10-12Analog Tuning - Range: ±2.2x10-8 ±2.2x10-8- Resolution: 1x10-111x10-11- Input: 0-2.5V into 100 kΩ 0-2.5V into 100 kΩWarm-up Time<130 s<180 sSolderHand solder using 63/37 Tin/Lead Solder with maximum soldering tip of 329°C (625°F)SpecificationsPart numbers 090-00218-101 and 090-00218-102All specifications at 25°C, Vcc =3.3VDC unless otherwise specifiedPart numbers 090-00218-003 and 090-00218-103..................................................................................................................................................................................................................................SpecificationsELECTRICAL SPECIFICATIONS RF Outptut - Frequency: 16.384 MHz - Format: CMOS - Amplitude: 0V to Vcc - Load impedance: 1 MΩ - Quantity: 11 PPS Output - Rise/fall time (10%-90%) at load capacitance 10pF: <10 ns - Pulse width: 400 µs - Level: 0V to Vcc - Logic High (V OH ) min: 2.80 V - Logic Low (V OL ) max: 0.30 V - Load impedance: 1 MΩ - Quantity: 1 1 PPS Input - Format: Rising edge - Low level: <0.5 V - High level: 2.5 V to Vcc - Input impedance: 1 MΩ - Quantity: 1 Serial Communications - Protocol: RS-232 - Format: CMOS 0V to Vcc - Tx/Rx impedance: 1 MΩ - Baud rate: 57600 Built-in Test Equipment (BITE) output - Format: CMOS 0V to Vcc - Load impedance: 1 MΩ - Logic: 0 = Normal operation 1 = Alarm Power Input - Operating: <120 mW - Warmup: <140 mW - Input Voltage (Vcc): 3.3 ± 0.1 VDC All specifications at 25°C, Vcc =3.3VDC unless otherwise specifiedPHYSICAL SPECIFICATIONS- Size:1.6” x 1.39” x 0.45”- Weight: <35 g- MTBF:>100,000 hoursENVIRONMENTAL SPECIFICATIONSOperating:- Operating temperature: -10°C to +70°C- Maximum frequency change over operating temp range (max. rate of change 0.5°C/minute):5x10-10- Frequency change over allowable input voltage range:<4x10-10- Magnetic sensitivity (≤2.0 Gauss):<9x10-11/Gauss - Radiated emissions: Compliant to FCC part 15, Class B, when mounted properlyonto host PCB- Vibration: Maintains lock under MIL-STD-810, method 514.5, procedure 1,7.7 grms- Humidity: 0 to 95% RH per MIL-STD-810, method 507.4Storage and Transport (non-operating):- Temperature: -55°C to +90°C - Shock (1 ms half-sine): 1000 g - Vibration:M IL-STD-810, method 514.5, procedure 1, 7.7 grmsPERFORMANCE PARAMETERSStability (Allan Deviation)ADEV -003 -103TAU = 1 sec 1.5x10-10 3x10-10 TAU = 10 sec 5x10-11 9.5x10-11TAU = 100 sec 1.5x10-11 3x10-11TAU = 1000 sec 5x10-129.5x10-12RF Output Phase Noise (SSB)1 Hz <-46 dBc/Hz 10 Hz <-66 dBc/Hz 100 Hz <-110 dBc/Hz 1000 Hz <-128 dBc/Hz 10000 Hz <-135 dBc/Hz 100,000 Hz<-140 dBc/HzFrequency Accuracy- Maximum offset at shipment: ±5x10-11- Maximum retrace (48 hrs off): ±5x10-11 - Aging, monthly*: <3x10-10 - Aging, yearly*: <1x10-9 - 1 PPS sync.: ±100 ns (*After 30 days of continuous operation)Digital Tuning - Range: ±2x10-8- Resolution: 1x10-12Analog Tuning - Range: ±2.2x10-8 - Resolution: 1x10-11- Input: 0 - 2.5V into 100 kΩWarm-up Time<130 sSolderHand solder using 63/37 Tin/Lead Solder with maximum soldering tip of 329°C (625°F)Part numbers 090-00218-004 and 090-00218-104..................................................................................................................................................................................................................................SpecificationsELECTRICAL SPECIFICATIONS RF Outptut - Frequency: 10.24 MHz - Format: CMOS - Amplitude: 0V to Vcc - Load impedance: 1 MΩ - Quantity: 11 PPS Output - Rise/fall time (10%-90%) at load capacitance 10pF: <10 ns - Pulse width: 400 µs - Level: 0V to Vcc - Logic High (V OH ) min: 2.80 V - Logic Low (V OL ) max: 0.30 V - Load impedance: 1 MΩ - Quantity: 1 1 PPS Input - Format: Rising edge - Low level: <0.5 V - High level: 2.5 V to Vcc - Input impedance: 1 MΩ - Quantity: 1 Serial Communications - Protocol: RS-232 - Format: CMOS 0V to Vcc - Tx/Rx impedance: 1 MΩ - Baud rate: 57600 Built-in Test Equipment (BITE) output - Format: CMOS 0V to Vcc - Load impedance: 1 MΩ - Logic: 0 = Normal operation 1 = Alarm Power Input - Operating: <120 mW - Warmup: <140 mW - Input Voltage (Vcc): 3.3 ± 0.1 VDC All specifications at 25°C, Vcc =3.3VDC unless otherwise specifiedPHYSICAL SPECIFICATIONS- Size:1.6” x 1.39” x 0.45”- Weight: <35 g- MTBF:>100,000 hoursENVIRONMENTAL SPECIFICATIONSOperating:- Operating temperature: -10°C to +70°C- Maximum frequency change over operating temp range (max. rate of change 0.5°C/minute):5x10-10- Frequency change over allowable input voltage range:<4x10-10- Magnetic sensitivity (≤2.0 Gauss):<9x10-11/Gauss - Radiated emissions: Compliant to FCC part 15, Class B, when mounted properlyonto host PCB- Vibration: Maintains lock under MIL-STD-810, method 514.5, procedure 1,7.7 grms- Humidity: 0 to 95% RH per MIL-STD-810, method 507.4Storage and Transport (non-operating):- Temperature: -55°C to +90°C - Shock (1 ms half-sine): 1000 g - Vibration:M IL-STD-810, method 514.5, procedure 1, 7.7 grmsPERFORMANCE PARAMETERSStability (Allan Deviation)ADEV -004 -104TAU = 1 sec 1.5x10-10 3x10-10 TAU = 10 sec 5x10-11 9.5x10-11TAU = 100 sec 1.5x10-11 3x10-11TAU = 1000 sec 5x10-129.5x10-12RF Output Phase Noise (SSB)1 Hz <-50 dBc/Hz 10 Hz <-70 dBc/Hz 100 Hz <-113 dBc/Hz 1000 Hz <-128 dBc/Hz 10000 Hz <-135 dBc/Hz 100,000 Hz<-140 dBc/HzFrequency Accuracy- Maximum offset at shipment: ±5x10-11- Maximum retrace (48 hrs off): ±5x10-11 - Aging, monthly*: <3x10-10 - Aging, yearly*: <1x10-9 - 1 PPS sync.: ±100 ns (*After 30 days of continuous operation)Digital Tuning - Range: ±2x10-8- Resolution: 1x10-12Analog Tuning - Range: ±2.2x10-8 - Resolution: 1x10-11- Input: 0 - 2.5V into 100 kΩWarm-up Time<130 sSolderHand solder using 63/37 Tin/Lead Solder with maximum soldering tip of 329°C (625°F)Part numbers 090-00218-006 and 090-00218-106................................................................................................................................................................................................................................SpecificationsELECTRICAL SPECIFICATIONS RF Outptut - Frequency: 5 MHz - Format: CMOS - Amplitude: 0V to Vcc - Load impedance: 1 MΩ - Quantity: 11 PPS Output - Rise/fall time (10%-90%) at load capacitance 10pF: <10 ns - Pulse width: 400 µs - Level: 0V to Vcc - Logic High (V OH ) min: 2.80 V - Logic Low (V OL ) max: 0.30 V - Load impedance: 1 MΩ - Quantity: 1 1 PPS Input - Format: Rising edge - Low level: <0.5 V - High level: 2.5 V to Vcc - Input impedance: 1 MΩ - Quantity: 1 Serial Communications - Protocol: RS-232 - Format: CMOS 0V to Vcc - Tx/Rx impedance: 1 MΩ - Baud rate: 57600 Built-in Test Equipment (BITE) output - Format: CMOS 0V to Vcc - Load impedance: 1 MΩ - Logic: 0 = Normal operation 1 = Alarm Power Input - Operating: <120 mW - Warmup: <140 mW - Input Voltage (Vcc): 3.3 ± 0.1 VDC All specifications at 25°C, Vcc =3.3VDC unless otherwise specifiedPHYSICAL SPECIFICATIONS- Size:1.6” x 1.39” x 0.45”- Weight: <35 g- MTBF:>100,000 hoursENVIRONMENTAL SPECIFICATIONSOperating:- Operating temperature: -10°C to +70°C- Maximum frequency change over operating temp range (max. rate of change 0.5°C/minute):5x10-10- Frequency change over allowable input voltage range:<4x10-10- Magnetic sensitivity (≤2.0 Gauss):<9x10-11/Gauss - Radiated emissions: Compliant to FCC part 15, Class B, when mounted properlyonto host PCB- Vibration: Maintains lock under MIL-STD-810, method 514.5, procedure 1,7.7 grms- Humidity: 0 to 95% RH per MIL-STD-810, method 507.4Storage and Transport (non-operating):- Temperature: -55°C to +90°C - Shock (1 ms half-sine): 1000 g - Vibration:M IL-STD-810, method 514.5, procedure 1, 7.7 grmsPERFORMANCE PARAMETERSStability (Allan Deviation)ADEV -006 -106TAU = 1 sec 1.5x10-10 3x10-10 TAU = 10 sec 5x10-11 9.5x10-11TAU = 100 sec 1.5 x10-11 3 x10-11TAU = 1000 sec 5x10-129.5x10-12RF Output Phase Noise (SSB)1 Hz <-53 dBc/Hz 10 Hz <-73 dBc/Hz 100 Hz <-116 dBc/Hz 1000 Hz <-131 dBc/Hz 10000 Hz <-138 dBc/Hz 100,000 Hz<-140 dBc/HzFrequency Accuracy- Maximum offset at shipment: ±5x10-11- Maximum retrace (48 hrs off): ±5x10-11 - Aging, monthly*: <3x10-10 - Aging, yearly*: <1x10-9 - 1 PPS sync.: ±100 ns (*After 30 days of continuous operation)Digital Tuning - Range: ±2x10-8- Resolution: 1x10-12Analog Tuning - Range: ±2.2x10-8 - Resolution: 1x10-11- Input: 0 - 2.5V into 100 kΩWarm-up Time<130 sSolderHand solder using 63/37 Tin/Lead Solder with maximum soldering tip of 329°C (625°F)SA.45s CSAC2300 Orchard Parkway © 2012 Symmetricom. Symmetricom and the Symmetricom logo are registered trademarks。
芯片级原子钟数字温控系统设计
2017年8月第37卷第4期宇航计测技术Journal o!Astronautic Metrology and MeasurementAug.,2017Vol.37,No.4文章编号=1000-7202(2017) 04-0030-05 D01:10.12060/j.issn.1000-7202.2017.04.07芯片级原子钟数字温控系统设计胡二猛刘瑞元赵建业(北京大学信息科学技术学院电子系，北京100871)摘要随着美国国防部先进项目研究局（D efence Advanced Research Projects Agency，DARPA)对微型定位 导航授时技术的提出以及无人驾驶技术的发展，芯片级原子钟的市场越来越受到重视。
稳定度是衡量芯片级原子 钟性能的关键指标，而温度又是影响芯片级原子钟稳定度指标的重要因素，因此高精度的温控系统是芯片级原子 钟稳定度的保障。
设计了一种高精度的数字温度控制系统，控温精度为2mK。
经过对比测试，使用该系统的芯片 级原子钟稳定度较以前有了较大的改善，千秒稳定度从7.57X10-12提高到4.99X10-12,处于世界先进水平。
关键词芯片级原子钟温度精度数字控温稳定度中图分类号:TH714 文献标识码:ADesign of Digital Temperature Control Systemfor Chip-scale Atomic ClockHU Er-meng LIU Rui-yuan ZHAO Jian-ye(D epartm en t o f Electronics，School o f Electronics Engineering and Com puter Sciences，Peking University，Beijing 100871，China)Abstract With the proposal of the Micro-PNT(Micro-Technology for Positioning,Navigation and Timing)by United States Department of Defense Advanced Projects Research Agency(DARPA)and the development of unmanned technology，the market of chip-scale atomic clock has attracted much attention.Stability is a key parameter of the performance of chip-scale atomic clock，which is affected by the accuracy of temperature control，so a high accuracy temperature-control system is very essential to the stability of chip-scale atomic clock.A digital temperature-control system with high accuracy is designed，and its precision is 2mK.The test results show，the stability of chip-scale atomic clock is greatly improved from7.57 X 10-12to 4.99 X 10-12，which is in a world level.Key words Chip scale Atomic clock Temperature Accuracy Digital temperature control Stability收稿日期：2016-11-21，修回日期：2017-02-24基金项目：国家自然科学基金（61535001)作者简介:胡二猛（1992-)，男，硕士研究生，主要研究方向：芯片级原子钟第4期芯片级原子钟数字温控系统设计.31 .1引言原子钟为当今世界提供了最精确的时间基准，目前由上海光机所自主研发的空间冷原子钟精度可 达3000万年误差一秒，世界上研制的精准的原子钟 已达到50亿年误差1秒⑴。
原子钟历史
原子钟依赖于微观世界中的周期现象（特别是跃迁辐射中的周期现象），这是自然界中最完美、最纯粹的周期现象。
它不损耗，不老化，振动周期比石英晶体短，所以原子钟的精度远高于以往任何一种钟，而且还可以测量更精细的时间间隔。
英国科学家最早研制的原子钟是铯原子钟。
铯在早期原子钟的生产中发挥了重要作用，由于其超精细能距大，在微波波段的跃迁辐射相对容易测定，而且它只有一种稳定的同位素，避免了提纯的麻烦。
此外，应该提到的是，美国和国家标准计量研究所于1949年研制的氨分子钟有时被称为第一原子钟。
原子钟的出现不仅改变了时间测量，也改变了空间测量。
1967年，人们将“秒”的定义从最初的天文定义改为原子钟的定义，即1秒等于“铯-133原子基态两个超精细能级跃迁对应的9192631770个辐射周期的持续时间”；1983年，人们进一步联系起来“米”与“秒”的定义，即一米等于“真空中的光1/299792458秒”。
在人类计量史上，这是一个引人注目的结果，因为传统上人们用空间距离（如日晷和时钟的刻度）来标记时间，但现在空间计量依赖于时间计量。
原子钟在诞生之初，其精度仅为每300年一秒。
经过半个多世纪的发展，其精度提高了几百万倍，而且还在不断提高。
同时，原子钟的种类也增加了。
工作物质已从铯和铷原子扩展到钙、锶甚至汞。
2009年，美国国家标准与计量研究所（NIST）的科学家研制出一种原子钟，其精度记录仅比每17亿年减少1秒。
原子钟是以汞离子为基础的。
它的工作波段在光学波段（传统的铯原子钟在微波波段），所以又称
光学钟。
光学钟的振动周期比铯原子钟短，所以除了精度更高外，可以测量的时间间隔也更精细。
CPT原子钟参数设计及其光谱实验研究
CPT原子钟参数设计及其光谱实验研究陈大勇;廉吉庆;涂建辉;翟浩;刘苏民【摘要】With the establishment of the theoretical model of passive CPT cesium atomic clock ,developing simulation analysis and research on the relationship between the CPT signal and the parameters of cesium vapor cell ,combined with the method of design and analysis for cesium vaporcell is established while the optimum design parameters areobtained .When the cesium vapor cell is cylindrical ,the diameter is 10mm ,the length of cesium vapor cell is 10 mm ,the cesium vapor cell operating tem-perature is 320 K ,the buffer gas pressure is 30 torr ,the cesium content is 100 μg .With multi-wavelength Doppler absorption spectroscopy experiment and CPT signal lock and frequency stablish test ,it is verified that the theoretical model is correct and providing for the method for the design and parameter optimization of high performance Chip-Scale-Atomic-Clock .%通过建立被动型CPT铯原子钟的理论模型,开展CPT信号与铯原子气室特性参量间关系的仿真分析和研究,建立铯原子气室设计及分析方法,得到了被动型CPT铯原子钟最佳设计参数,直径10 mm、长度10 mm、缓冲气体为N2的圆柱形铯原子气室,最佳工作参数为:工作温度为320 K、气体压强值50 Torr.并经多波长多普勒吸收光谱、CPT信号锁定及频率稳定度测试等实验,验证了理论模型的正确性,为开展高性能芯片级CPT铯原子钟的设计、参数优化提供了一种研究方法.【期刊名称】《光谱学与光谱分析》【年(卷),期】2017(037)007【总页数】5页(P2254-2258)【关键词】CPT原子钟;设计;光谱实验;研究【作者】陈大勇;廉吉庆;涂建辉;翟浩;刘苏民【作者单位】兰州空间技术物理研究所, 甘肃兰州 730000;真空技术与物理重点实验室, 甘肃兰州 730000;真空技术与物理重点实验室, 甘肃兰州 730000;兰州空间技术物理研究所, 甘肃兰州 730000;真空技术与物理重点实验室, 甘肃兰州730000;真空技术与物理重点实验室, 甘肃兰州 730000;兰州空间技术物理研究所, 甘肃兰州 730000;真空技术与物理重点实验室, 甘肃兰州 730000;真空技术与物理重点实验室, 甘肃兰州 730000;兰州空间技术物理研究所, 甘肃兰州 730000;真空技术与物理重点实验室, 甘肃兰州 730000;真空技术与物理重点实验室, 甘肃兰州 730000;兰州空间技术物理研究所, 甘肃兰州 730000;真空技术与物理重点实验室, 甘肃兰州 730000;真空技术与物理重点实验室, 甘肃兰州 730000【正文语种】中文【中图分类】TN29被动型CPT(coherent population trapping)原子钟由于不需要微波谐振腔，可以实现原子钟的微型化甚至芯片级，是目前原子钟发展的一个趋势。
原子钟精确测量时间的科学壮举
原子钟精确测量时间的科学壮举时间，是我们日常生活中无法逃避的现实。
我们用时间来划分一天的工作和休息，用时间来衡量活动的快慢，用时间来安排生活的各个方面。
然而，关于时间的精确测量一直是一个挑战。
幸运的是，科学家们的努力使得原子钟成为目前世界上最精确的时间测量工具之一。
原子钟是基于原子物理学原理的设备，利用原子的稳定振荡特性来精确测量时间。
在这个精密的仪器中，原子的振荡频率被作为“秒”的定义基准。
相比传统的机械钟或者石英钟，原子钟能够提供更高的准确性和稳定性。
原子钟的核心技术是基于原子的共振现象。
其中最常用的一种原子钟是铯原子钟。
铯是一种碱金属元素，它具有非常稳定的原子结构。
在这种钟中，铯原子通过外加的射频电磁场被激发到特定能级，然后在高能态和低能态之间发生共振跃迁。
这个共振频率被定义为“原子钟的秒”。
根据国际单位制的定义，一秒被定义为铯原子跃迁所需的时间。
原子钟的制造非常精密和复杂。
首先，科学家们需要冷却铯原子以减小其热运动引起的频率不稳定性。
通常，液氮或者液氦被用来冷却原子，使其停止热运动。
接下来，激光系统被使用来与铯原子进行相互作用，激发其共振转变。
最后，通过精确计数原子的共振频率和参考标准，原子钟能够提供非常准确的时间测量。
原子钟的精确度非常高，通常在几个亿分之一秒（纳秒）的范围内。
这种准确性对于许多领域来说至关重要。
比如，全球的通信和导航系统都依赖于原子钟来同步信息并计算精确的时间间隔。
空间探测器和卫星也需要原子钟来精确测量其位置和速度。
除了铯原子钟，还有其他类型的原子钟，如氢原子钟和铯氢混合原子钟。
每一种原子钟都有其特定的优势和应用领域。
无论是铯原子钟还是其他类型的原子钟，它们都是现代科学技术中不可或缺的一部分。
原子钟的发展和应用推动了时间测量领域的进步。
随着科学技术的不断发展，原子钟的精确度将继续提高，甚至可能达到更小的时间单位。
同时，原子钟的应用也将不断扩大到更多的领域，为人类的日常生活和科学研究提供更精准的时间参考。
[惯性技术之窗] 芯片级原子钟(CSAC)——目前最小军民两用原子钟(二)
![[惯性技术之窗] 芯片级原子钟(CSAC)——目前最小军民两用原子钟(二)](https://img.taocdn.com/s3/m/c976e792a0116c175f0e48ce.png)
[惯性技术之窗] 芯片级原子钟（CSAC）——目前最小军民两用原子钟（二）（继续）世界上首款芯片级原子钟CSAC SA.45 CSAC SA.45s采用CPT现象解调原子频率，并通过新颖的电子结构，实现了小型化和低功耗的芯片级原子钟。
SA.45s 电路系统包含低功耗数字信号处理器、高分辨率微波合成器和模拟信号处理。
微波输出源自可调谐的晶体振荡器，并施加到物理表头内的激光上，以便产生CPT 解调所需的两个边带。
在通过铯蒸汽原子气室后，光电探测器检测发射过来的激光。
基于所测量的原子响应，微处理器调整了晶体振荡器的频率。
物理系统（图10）中包含了“中心叠层”和“热绝缘系统”。
中心叠层包含VCSEL、原子气室和光电二极管。
从VCSEL发出的激光在通过原子气室前，会因为通过单元间隔柱而发散，并在光电探测器上被检测。
图10 CSAC SA.45s物理表头及在电路系统中的位置热绝缘系统的功能主要是支撑中心叠层，同时为周围环境提供高度的隔热，最大限度地减小所需要的加热器功率。
热绝缘系统包含上下悬架和真空封装。
真空封装消除了由于气体导热和对流而产生的热损失。
通过悬架设计，使导热造成的热损失减少到最小。
上下悬架由一层薄的聚酰亚胺薄膜制成，带有金属图案导线，可与中心叠层来回发送信号。
中心叠层需要悬挂在两个聚酰亚胺“圆柱头”之间。
这种结构非常牢固，能够承受超过1000g （1ms 半正弦波的机械冲击，并提供极高的热阻（>5000℃/W）。
此外，将电气连接图案印在聚酰亚胺上，无需机械支持，因此它们的尺寸由电气要求而不是机械要求来确定，从而减少了由于热通过连接传导而产生的热负荷。
芯片级原子钟的应用鉴于芯片级原子钟的性能基准，目前“最适合”芯片级原子钟的应用将是：海底地震感测。
在海底地震感测技术中，多种水下传感系统都依赖于精确定时的有效性。
由于在水下难以从GPS 获得精确的时间，因此这类传感器通常会依赖于恒温晶振，用以从传感器内获得稳定和准确的时间戳。
芯片级原子钟评测报告
CSAC-SA.45s原子钟测试——儒科测评报告测评概述：全球最小的芯片级原子钟CSAC—SA.45s现已经正式登陆中国，儒科电子对首批到货的CSAC进行了相关性能测试以期为客户选型提供依据。
本次测试，使用我们公司自主研制的高性能GPS同步时钟——TG100系统作为测试参考源，分别对CSAC的10MHz输出和1PPS相关指标进行了测试，并同其它铷钟进行了一个横向比较。
测试内容包括CSAC的10MHz的频率准确度、短期稳定性、相位噪声，以及1PPS信号的定时精度、锁定频率准确度、保持稳定性和24小时保持等关键指标。
此外，还对CSAC的锁定时间和功耗进行了测试。
测试设备：测试参考源：TG100-FTS同步时钟的10MHz输出以及1PPS秒脉冲；频率计数器：Agilent 53132A；相噪测试仪：Symmetricom TSC 5125A；万用表、直流电源设备。
待测设备：Symmetricom SA.45s芯片级原子钟。
测试连接：1.使用TG100同步时钟作为参考源（连续工作24小时以上）测试CSAC的1PPS和10MHz输出；2.使用屋顶天线，收星状况良好。
图表1 测试连接测试综述：CSAC 的各项指标测试良好； ☆锁定时间约为：60s ；☆开机功耗约为：110mW ，稳定运行时功耗约为：90mW ； ☆10MHz 输出的相噪、短稳、频率准确度和普通铷钟水平相当； ☆1PPS 锁定输出峰峰值实测67小时保持在20ns 以内； ☆1PPS 锁定67小时平均频率准确度为：2.32E-14； ☆1PPS 保持24小时相差为：4us ；☆1PPS 保持24小时平均频率准确度为：4.72E-11。
测试项目：一、开机锁定时间原子钟型号锁定时间CSAC原子钟约60sSA.3xm系列铷钟约5分钟X72系列铷钟约6分钟图表 2 开机锁定时间对比二、开机功耗原子钟型号开机功耗稳定运行时功耗CSAC原子钟110 mW 90m WSA.3xm系列14 W 5 WX72系列18 W（最大）10 W图表 3 功耗对比注明：测试的时候要求测试环境的温度在25℃左右三、10MHz方波输出1.频率准确度图表 4 频率准确度2.相位噪声图表 5 相位噪声CSAC锁定时候的10MHz频率准确度可以达到E-10量级CSAC的10MHz输出的相噪与普通铷钟SA.31m性能相当相位噪声（10MHz）SA.31m CSAC实测结果@1Hz<-65dBc/Hz <-64.54dBc/Hz@10Hz <-85dBc/Hz <-93.75dBc/Hz@100Hz<-112dBc/Hz <-120.67dBc/Hz@1KHz<-130dBc/Hz <-132.79dBc/Hz@10KHz <-140dBc/hz <-140.43dBc/Hz图表 6 相噪对比3.短期稳定性CSAC的短期稳定性与普通铷钟SA.31m的性能相当图表 7 阿伦方差10MHz输出短期稳定性SA.31m CSAC实测结果@1S ≤5E-11 5.31E-11@10S ≤2.5E-11 1.96E-11@100S ≤1E-11 7.90E-12图表 8 短稳对比四、1PPS相关指标1.1PPS定时精度（锁定到GPS）1PPS输出峰峰值实测67小时保持在20ns以内图表 9 锁定PPS精度1PPS定时精度测试数据采集从CSAC刚开始锁定到外部1PPS时进行记录。
原子钟的几种常见类型之欧阳德创编
原子钟的几种常见类型时间：2021.03.07 创作：欧阳德摘要本文按出现的时间顺序介绍几种常用原子钟(光谱灯抽运铷原子钟、光谱灯抽运铯原子钟、磁选态铯原子束钟、激光抽运铯原子束钟、激光冷却冷原子喷泉钟、积分球冷却原子钟)的基本原理。
原子钟是利用原子或分子的能级跃迁的辐射频率来锁定外接振荡器频率的频率测量标准装置的俗称，通称为量子频率标准或原子频标。
其工作原理可用图1来描述：图1一个受控的标准频率发生器产生的信号经过倍频和频率合成转换成为频率接近于原子跃迁频率的信号，激励原子产生吸收或受激发射的频率响应信号，呈共振曲线形状，称为原子谱线，其中心频率即原子跃迁频率为，线宽为Δν。
若经过转换的受控振荡器频率与原子跃迁频率不符，原子做出的响应信号通过伺服反馈系统来矫正振荡频率，直到使其与原子频率符合为止。
这样就使受控振荡器频率始终稳定在原子跃迁频率上，从而实现使其振荡频率锁定于原子跃迁频率的目的。
光谱灯抽运铷原子钟光抽运汽室频标用碱金属原子基态两个超精细结构能级之间跃迁的辐射频率作为标准频率，它处在微波波段。
在磁场中，这两个能级都有塞曼分裂，作为标准频率的跃迁是其中两个磁子能级=0之间的跃迁，它受磁场影响最小。
若用合适频率单色光照射原子系统，使基态一个超精细能级上的原子被共振激发，而自发辐射回到基态时可能落到所有能级，原子就会集中到一个基态能级，极大地偏离玻尔兹曼分布，这就是光抽运效应。
这里选择抽运光起着关键作用。
在20世纪60年代初，激光器刚发明尚无法利用，唯一可用的共振光源是光谱灯。
一般光谱灯是由同类原子发光，它的光谱成分能使基态两个超精细能级上的原子都被激发，因而不能有效地实现选择吸收，起到光抽运作用。
幸好对铷原子，可以有一个巧妙的办法。
铷原子有两种稳定同位素：和，其丰度分别为72. 2%和27. 8%。
它们各有能级间距为3036MHz和6835MHz 的两个超精细能级，其共振光的频率分布如图2所示。
芯片原子钟 产品介绍 DS_SA45s_CSAC.
Key Features• Power consumption <120 mW• Less than 17 cc volume, 1.6” x 1.39” x 0.45” • Aging <3.0E-10/month• 10 MHz CMOS-compatible output• 1 PPS output and 1 PPS input for synchronization • Hermetically sealed• RS-232 interface for monitoring and controlApplications• Underwater sensor systems• GPS receivers• Dismounted military radios• Anti-IED jamming systems• Autonomous sensor networks• Unmanned vehiclesWith an extremely low power consumption of <120 mW and a volume of <17 cc, the Symmetricom ® SA.45s Chip Scale Atomic Clock (CSAC brings the accuracy and stability of an atomic clock to portable applications for the first time.The SA.45s provides 10 MHz and 1 PPS outputs at standard CMOS levels, with short-term stability (Allan Deviation of 1.5E-10 @ 1 sec, long-term aging of 3E-10/month, and maximum frequency change of 5E-10 over an operating temperature range of -10°C to +70°C. The unit can also be ordered with a wider temperature range (Option 002 of -40°C to +85°C, with slightly higher power consumption and a wider maximum frequency change over temperature.SA.45s CSACChip Scale Atomic ClockThe SA.45s CSAC accepts a 1 PPS input that may be used to synchronize the unit’s 1 PPS output to an external reference clock with ±100 ns accuracy. The CSAC can also use the 1 PPS input to discipline its phase and frequency to within 1 ns and 1.0E-12, respectively.A standard CMOS-level RS-232 serial interface is built in to the SA.45s. This is used to control and calibrate the unit and also to provide a comprehensive set of status monitors. The interface is also used to set and read the CSAC’s internal time-of-day clock.DATA SHEETSymmetricom invented portable atomictimekeeping with QUANTUM™, the worldʼs first family of miniature and chip scale atomic clocks.Choose QUANTUM™ class for best-in-class stability, size, weight and power consumption.Low Power Consumption By DesignEvery part of the SA.45s CSAC has been engineered for low power consumption. It starts with the physics package, shown here in a cutaway view. A vertical-cavity surface-emitting laser (VCSEL that has been highly optimized for this specific application illuminates the atomic vapor resonance cell, and the light that gets through the cell is then detected by the photodetector. The photodetector outputsignal drives a feedback loop which is used to achieve atomic resonance using the principles of coherent population trapping (CPT. The entire physics package has a volume of only 0.35 cm3, and the actual resonance cell itself has a volume of only 2 mm3. It is this extremely small size, plus the fact that it is surrounded by a vacuum within the physics package, that allows the entire physics package to be powered by about 15 mW. As the cutaway drawing shows, the only way the physics package connects with the outside world is through a top and bottom polyimide suspension. All signals that need to go to or from the center stack-up are carried on traces that are printed on the suspensions. And because the suspensions are connected to a frame that is engineered to be slightly shorter than the center stack-up, they are in tension and serve to hold the stack-up in place. The result is a very small, highly thermally isolated, and robust physics package with excellent performance. All of the electronics that surround the physics package, and which turn it into a fully functional clock, have also been engineered for low powerconsumption. Even the CSAC controller’s firmware routines have been optimized for low power consumption.Low Power Is Just The BeginningAn atomic clock that consumes only 120 mW of power (125 mW for option 002 instead of 10 W or more gives system designers a new and important degree of freedom. But that is just the beginning. Because of its small size and high thermal isolation, the SA.45s CSAC warms up in <130 sec, compared to 8 minutes or more for conventional atomic clocks. Also, power consumption during warm-up is only 140 mW, while conventional atomic clocks will often consume two times their steady-state power during warm-up. Fi nally, the CSAC’s power consumption variation vs. temperature is negligible, while otheratomic clocks can show variations of 200% or more across their specified temperature range.The World's Smallest Atomic ClockPower consumption and size are both critical to enabling portable applications, and the SA.45s is by far the smallestatomic clock available. For example, while the SA.45s CSAC does not quite equal the performance of Symmetricom’s XPRO rubidium oscillator, the figure shows it has approximately 1/30th the volume—and 1/14th the weight—of the XPRO. Conversely, the SA.45s has much higher performance than OCXOs, and still offers a 4x reduction in volume compared to popular OCXO package sizes.SA.45s CSACSA.45s CSAC is 1/30th the volumeof the XPROS A .45s CS ACX P R O030510152025Underwater Sensor Systems Underwater sensors are used in seismic research, oil exploration and many other applications. Sensors designed to lie on the ocean floor will typically include a hydrophone, a geophone and a very stable clock to time-stamp the data collected by the sensor. Because GPS signals can’t penetrate water, oven-controlled crystal oscillators (OCXO’s have been used to provide the accuracy needed for mosttime-stamping applications.But the SA.45s CSAC is a nearly ideal clock for these underwater applications. Because it consumes 1/10th to 1/30th the power of an OCXO, it requires much less battery power, resulting in smaller and lower-cost sensors, or alternatively, sensors with a much longe r mission life. The SA.45s CSAC’s aging rate, which can be 1/100th of even a good OCXO, means that time-stamping errors caused by drift are greatly reduced. Finally, the SA.45s CSAC’s superior temperature coefficient means that when sensors are calibrated to GPS on a warm boat deck, but then dropped into cold ocean water of several hundred meters depth, the offset error produced by this temperature change is minimized.Portable Military SystemsMany advancements in military electronics are aimed at bringing the networked battlefield to the tactical edge, i.e. the individual warfighter. But there are limitations on how many pieces of gear and how much battery weight a warfighter can be expected to carry. This is especially true when operations are carried out in rugged terrain and/or high altitude. The CSAC’s small size, light weight, and extremely low power consumption can help in a number of systems:Dismounted IED Jammers: size and weight are always at a premium, so the SA.45s CSAC is an attractive option. Also, power not applied to the timing subsystem is power that can be applied to the jammer itself, or that can be used to extend mission life. The CSAC's precise synchronization is critical to prevent self-jamming, while its ultra-stable holdover is equally vital in GPS-denied environments. Dismounted Radio Systems: the SA.45s CSAC helps to minimize size, weight, and power consumption. At the same time, it provides the high accuracy required by many modern high-bandwidth waveforms, and it provides the stability needed to maintain network synchronization in GPS-denied environments.GPS Receivers: using the SA.45s CSAC as a timebase, military GPS receivers can achieve greatly reduced Time To Subsequent Fix (TTSF for 24 hours or more. It also becomes possible to operate with only three satellites in view (instead of the usual 4, a distinct advantage in manyurban settings.Unmanned Aerial VehiclesAs the number of applications for civil and military umanned aerial vehicles (UAVs rapidly expands, the suppliers of payloads for these vehicles are being pressured to increase their functionality. In doing so, they find themselves bumping into limitations in size, weight and power.The SA.45s CSAC can help in all threeareas, with a volume of <17 cm³, a weight of <35 g and power consumption of <125 mW. In fact, in some applications the CSAC is attractive solely because, when compared to conventional rubidium oscillators(~20 W in warm-up, ~10 W in steady state, its low power consumption simplifies thermal management issues.Many UAV’s rely on GPS, and the SA.45s CSAC can be disciplined by the 1 PPS output from a GPS receiver, and provide a stable signal that can be used by C4I or SIGINT payloads. And of course, should GPS be lost due to natural interference or jamming, the SA.45s CSAC provides a stable holdover signal that meets the requirements of even long-endurancemissions.1 Tune2 N/A3 N/A4 BITE5 Tx6 Rx7 Vcc8 GND9 1 PPS IN 10 1 PPS OUT 11 N/A 1210 MHz OUTPIN NO. FUNCTIONMechanical InterfaceOptions to Meet a Wider Range of ApplicationsThe standard SA.45s CSAC (options 001 and 002 provides an output frequency of 10MHz. However, other frequencies are available: option 006 provides a 5 MHz output, option 003 provides 16.384 MHz, and option 004 provides 10.24 MHz. Other frequencies are also possible; contact Symmetricom for details.For applications where the very best Allan Deviation (ADEV is not required, the SA.45s CSAC is also available with less stringent ADEV specifications at a lower price. For example, at TAU = 1sec, option 001 has an ADEV specification of 1.5E-10, while option 101 has a specification of 3E-10.SA.45s CSAC Options 001 and 002. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ELECTRICAL SPECIFICATIONS-001 -002RF Outptut- Frequency: 10 MHz 10 MHz- Format: CMOS CMOS - Amplitude:0V to Vcc 0V to Vcc- Load impedance: 1 MΩ 1 MΩ- Quantity: 1 11 PPS Output- Rise/fall time (10%-90%at load capacitance 10pF: <10 ns <10 ns- Pulse width: 400 µs 400 µs- Level:0V to Vcc 0V to Vcc - Logic High (VOH min: 2.80 V 2.80 V- Logic Low (VOL max: 0.30 V 0.30 V - Load impedance: 1 MΩ 1 MΩ- Quantity: 111 PPS Input- Format: Rising edge Rising edge- Low level: <0.5 V<0.5 V- High level:2.5 V to Vcc 2.5 V to Vcc- Input impedan ce: 1 MΩ 1 MΩ- Quantity:1 1Serial Communications- Protocol: RS232RS232- Format:CMOS 0V to Vcc CMOS 0V to Vcc- Tx/Rx impedance: 1 MΩ 1 MΩ- Baud rate:57600 57600Built-in Test Equipment (BITE output- Format: CMOS 0V to Vcc CMOS 0V to Vcc- Load impedanc e: 1 MΩ 1 MΩ- Logic: 0 = Normal operation 0 = Normal operation 1 = Alarm 1 = AlarmPower Input- Operating: <120 mW <125 mW- Warmup:<140 mW <140 mW- Input voltage (Vcc:3.3 ± 0.1 VDC3.3 ± 0.1 VDCPHYSICAL SPECIFICATIONS- Size: 1.6” x 1.39” x 0.45” 1.6” x1.39” x 0.45” - Weight: <35 g<35 g- MTBF:>100,000 hours>50,000 hoursENVIRONMENTAL SPECIFICATIONSOperating:- Operating temperature: -10°C to +70°C -40°C to +85°C- Maximum frequency change over operating temp range (max. rate of change 0.5 °C/minute: 5x10-10 1x10-9- Frequency change over allowable input voltage range: <4x10-10<4x10-10ENVIRONMENTAL SPECIFICATIONS (Continued-001 -002- Magnetic sensitivity(≤2.0 Gauss:<9x10-11/Gauss <9x10-11/Gauss- Radiated emissions: Compliant to FCC Compliant to FCC part 15, Class B, part 15, Class B, when mounted when mounted properly onto properly ontohost PCB.host PCB.- Vibration: Maintains lock under Maintains lock under MIL-STD-810, MIL-STD-810, Method 514.5,Method 514.5,Procedure 1, 7.7 grms Procedure 1, 7.7 grms- Humidity: 0 to 95% RH per 0 to 95% RH per MIL-STD-810, MIL-STD-810,Method 507.4.Method 507.4Storage and Transport (non-operating:- Temperature: - 55°C to +90°C - 55°C to +90°C- Shock (1 ms half-sine: 1000 g 1000 g- Vibration: MIL-STD-810, MIL-STD-810, Method 514.5, Method 514.5,Procedure 1, 7.7 grmsProcedure 1, 7.7 grmsPERFORMANCE PARAMETERSStability (Allan Deviation ADEVTAU = 1 sec 1.5x10-10 2x10-10TAU = 10 sec 5x10-11 7x10-11TAU = 100 sec 1.5x10-11 2x10-11TAU = 1000 sec5x10-127x10-12RF Output Phase Noise (SSB1 Hz <-50 dBc/Hz <-50 dBc/Hz10 Hz <-70 dBc/Hz <-70 dBc/Hz100 Hz <-113 dBc/Hz <-113 dBc/Hz1000 Hz <-128 dBc/Hz <-128dBc/Hz10000 Hz <-135 dBc/Hz <-135 dBc/Hz100,000 Hz<-140 dBc/Hz <-140 dBc/HzFrequency Accuracy- Maximum offset at shipment: ±5x10-11 ±5x10-11- Maximum retrace (48 hrs off: ±5x10-11 ±5x10-11- A ging, monthly*: <3x10-10 <3x10-10- Aging, yearly*: <1x10-9 <1x10-9- 1 PPS Sync.: ±100 ns ±100 ns(*After 30 days of continuous operationDigital Tuning- Range: ±2x10-8 ±2x10-8- Resolution: 1x10-12 1x10-12Analog Tuning- Range: ±2.2x10-8 ±2.2x10-8- Resolution: 1x10-111x10-11- Input: 0-2.5V into 100 kΩ 0-2.5V into 100 kΩWarm-up Time<130 s<180 sSolderHand solder using 63/37 Tin/Lead Solder with maximum soldering tip of 329°C (625°FSpecificationsPart numbers 090-00218-001 and 090-00218-002All specifications at 25°C, Vcc=3.3VDC unless otherwise specifiedSA.45s CSAC Options 101 and 102. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ELECTRICAL SPECIFICATIONS-101 -102RF Outptut- Frequency: 10 MHz 10 MHz- Format: CMOS CMOS - Amplitude:0V to Vcc 0V to Vcc- Load impedance: 1 MΩ 1 MΩ- Quantity: 1 11 PPS Output- Rise/fall time (10%-90%at load capacitance 10pF: <10 ns <10 ns- Pulse width: 400 µs 400 µs- Level:0V to Vcc 0V to Vcc - Logic High (VOH min: 2.80 V 2.80 V- Logic Low (VOL max: 0.30 V 0.30 V - Load impedance: 1 MΩ 1 MΩ- Quantity: 111 PPS Input- Format: Rising edge Rising edge- Low level: <0.5 V<0.5 V- High level:2.5 V to Vcc 2.5 V to Vcc- Inp ut impedance: 1 MΩ 1 MΩ- Quantity:1 1Serial Communications- Protocol: RS232RS232- Format:CMOS 0V to Vcc CMOS 0V to Vcc- Tx/Rx impedance: 1 MΩ 1 MΩ- Baud rate:57600 57600Built-in Test Equipment (BITE output- Format: CMOS 0V to Vcc CMOS 0V to Vcc- Loa d impedance: 1 MΩ 1 MΩ- Logic: 0 = Normal operation 0 = Normal operation 1 = Alarm 1 = AlarmPower Input- Operating: <120 mW <125 mW- Warmup:<140 mW <140 mW- Input voltage (Vcc:3.3 ± 0.1 VDC3.3 ± 0.1 VDCPHYSICAL SPECIFICATIONS- Size: 1.6” x 1.39” x 0.45” 1.6” x 1.39” x 0.45” - Weight: <35 g<35 g- MTBF:>100,000 hours>50,000 hoursENVIRONMENTAL SPECIFICATIONSOperating:- Operating temperature: -10°C to +70°C -40°C to +85°C- Maximum frequency change over operating temp range (max. rate of change 0.5 °C/minute: 5x10-10 1x10-9- Frequency change over allowable input voltage range: <4x10-10<4x10-10ENVIRONMENTAL SPECIFICATIONS (Continued-101 -102- Magnetic sensitivity(≤2.0 Gauss:<9x10-11/Gauss <9x10-11/Gauss- Radiated emissions: Compliant to FCC Compliant to FCC part 15, Class B, part 15, Class B, when mounted when mounted properly onto properly ontohost PCB.host PCB.- Vibration: Maintains lock under Maintains lock under MIL-STD-810, MIL-STD-810, Method 514.5,Method 514.5,Procedure 1, 7.7 grms Procedure 1, 7.7 grms- Humidity: 0 to 95% RH per 0 to 95% RH per MIL-STD-810, MIL-STD-810,Method 507.4.Method 507.4Storage and Transport (non-operating:- Temperature: - 55°C to +90°C - 55°C to +90°C- Shock (1 ms half-sine: 1000 g 1000 g- Vibration: MIL-STD-810, MIL-STD-810, Method 514.5, Method 514.5,Procedure 1, 7.7 grmsProcedure 1, 7.7 grmsPERFORMANCE PARAMETERSStability (Allan DeviationADEVTAU = 1 sec 3x10-10 3x10-10TAU = 10 sec 9.5x10-11 9.5x10-11TAU = 100 sec 3x10-11 3x10-11TAU = 1000 sec9.5x10-129.5x10-12RF Output Phase Noise (SSB1 Hz <-50 dBc/Hz <-50 dBc/Hz10 Hz <-70 dBc/Hz <-70 dBc/Hz100 Hz <-113 dBc/Hz <-113 dBc/Hz1000 Hz <-128 dBc/Hz <-128dBc/Hz10000 Hz <-135 dBc/Hz <-135 dBc/Hz100,000 Hz<-140 dBc/Hz <-140 dBc/HzFrequency Accuracy- Maximum offset at shipment: ±5x10-11 ±5x10-11- Maximum retrace (48 hrs off: ±5x10-11 ±5x10-11- A ging, monthly*: <3x10-10 <3x10-10- Aging, yearly*: <1x10-9 <1x10-9- 1 PPS Sync.: ±100 ns ±100 ns(*After 30 days of continuous operationDigital Tuning- Range: ±2x10-8 ±2x10-8- Resolution: 1x10-12 1x10-12Analog Tuning- Range: ±2.2x10-8 ±2.2x10-8- Resolution: 1x10-111x10-11- Input: 0-2.5V into 100 kΩ 0-2.5V into 100 kΩWarm-up Time<130 s<180 sSolderHand solder using 63/37 Tin/Lead Solder with maximum soldering tip of 329°C (625°FSpecificationsPart numbers 090-00218-101 and 090-00218-102All specifications at 25°C, Vcc=3.3VDC unless otherwise specifiedSA.45s CSAC Options 003 and 103Part numbers 090-00218-003 and 090-00218-103. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SpecificationsELECTRICAL SPECIFICATIONSRF Outptut- Frequency: 16.384 MHz- Format: CMOS - Amplitude: 0V to Vcc- Load impedance: 1 MΩ - Quantity: 11 PPS Output - Rise/fall time (10%-90% at load capacitance 10pF: <10 ns- Pulse width: 400 µs - Level: 0V to Vcc - Logic High (VOH min: 2.80 V - Logic Low (VOL max: 0.30 V - Load impedance: 1 MΩ - Quantity: 1 1 PPS Input- Format: Rising edge - Low level: <0.5 V - High level: 2.5 V to Vcc - Input impedance: 1 MΩ - Quantity: 1 Serial Communications- Protocol: RS-232 - Format: CMOS 0V to Vcc - Tx/Rx impedance: 1 MΩ - Baud rate: 57600 Built-in Test Equipment (BITE output- Format: CMOS 0V to Vcc - Loadimpedance: 1 MΩ - Logic: 0 = Normal operation 1 = AlarmPower Input- Operating:<120 mW- Warmup: <140 mW- Input Voltage (Vcc: 3.3 ± 0.1 VDC All specifications at 25°C, Vcc =3.3VDC unless otherwise specifiedPHYSICAL SPECIFICATIONS- Size:1.6” x 1.39” x 0.45” - Weight: <35 g- MTBF:>100,000 hoursENVIRONMENTAL SPECIFICATIONSOperating:- Operating temperature: -10°C to +70°C- Maximum frequency change over operating temp range (max. rate of change0.5°C/minute:5x10-10- Frequency change over allowable input voltage range:<4x10-10- Magnetic sensitivity (≤2.0 Gauss:<9x10-11/Gauss - Radiated emissions: Compliant to FCC part 15, Class B, when mounted properlyonto host PCB- Vibration: Maintains lock under MIL-STD-810, method 514.5, procedure 1,7.7 grms- Humidity: 0 to 95% RH per MIL-STD-810, method 507.4Storage and Transport (non-operating:- Temperature: -55°C to +90°C - Shock (1 ms half-sine: 1000 g - Vibration:M IL-STD-810, method 514.5, procedure 1, 7.7 grmsPERFORMANCE PARAMETERSStability (Allan DeviationADEV -003 -103TAU = 1 sec 1.5x10-10 3x10-10 TAU = 10 sec 5x10-11 9.5x10-11TAU = 100 sec 1.5x10-11 3x10-11TAU = 1000 sec 5x10-129.5x10-12RF Output Phase Noise (SSB1 Hz <-46 dBc/Hz10 Hz <-66 dBc/Hz 100 Hz <-110 dBc/Hz 1000 Hz <-128 dBc/Hz 10000 Hz <-135 dBc/Hz 100,000 Hz<-140 dBc/HzFrequency Accuracy- Maximum offset at shipment: ±5x10-11- Maximum retrace (48 hrs off: ±5x10-11 - Aging, monthly*: <3x10-10 - Aging, yearly*: <1x10-9 - 1 PPS sync.: ±100 ns(*After 30 days of continuous operationDigital Tuning- Range: ±2x10-8- Resolution: 1x10-12Analog Tuning- Range: ±2.2x10-8 - Resolution: 1x10-11- Input: 0 - 2.5V into 100 kΩWarm-up Time<130 sSolderHand solder using 63/37 Tin/Lead Solder with maximum soldering tip of 329°C (625°FSA.45s CSAC Options 004 and 104Part numbers 090-00218-004 and 090-00218-104. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SpecificationsELECTRICAL SPECIFICATIONSRF Outptut- Frequency: 10.24 MHz- Format: CMOS - Amplitude: 0V to Vcc- Load impedance: 1 MΩ - Quantity: 11 PPS Output - Rise/fall time (10%-90% at load capacitance 10pF: <10 ns- Pulse width: 400 µs - Level: 0V to Vcc - Logic High (VOH min: 2.80 V - Logic Low (VOL max: 0.30 V - Load impedance: 1 MΩ - Quantity: 1 1 PPS Input- Format: Rising edge - Low level: <0.5 V - High level: 2.5 V to Vcc - Input impedance: 1 MΩ - Quantity: 1 Serial Communications- Protocol: RS-232 - Format: CMOS 0V to Vcc - Tx/Rx impedance: 1 MΩ - Baud rate: 57600 Built-in Test Equipment (BITE output- Format: CMOS 0V to Vcc - Load impedance: 1 MΩ - Logic: 0 = Normal operation 1 = AlarmPower Input- Operating:<120 mW- Warmup: <140 mW- Input Voltage (Vcc: 3.3 ± 0.1 VDC All specifications at 25°C, Vcc =3.3VDC unless otherwise specifiedPHYSICAL SPECIFICATIONS- Size:1.6” x 1.39” x 0.45” - Weight: <35 g- MTBF:>100,000 hoursENVIRONMENTAL SPECIFICATIONSOperating:- Operating temperature: -10°C to +70°C- Maximum frequency change over operating temp range (max. rate of change 0.5°C/minute:5x10-10- Frequency change over allowable input voltage range:<4x10-10- Magnetic sensitivity (≤2.0 Gauss:<9x10-11/Gauss - Radiated emissions: Compliant to FCC part 15, Class B, when mounted properlyonto host PCB- Vibration: Maintains lock under MIL-STD-810, method 514.5, procedure 1,7.7 grms- Humidity: 0 to 95% RH per MIL-STD-810, method 507.4Storage and Transport (non-operating:- Temperature: -55°C to +90°C - Shock (1 ms half-sine: 1000 g - Vibration:M IL-STD-810, method 514.5, procedure 1, 7.7 grmsPERFORMANCE PARAMETERSStability (Allan DeviationADEV -004 -104TAU = 1 sec 1.5x10-10 3x10-10 TAU = 10 sec 5x10-11 9.5x10-11TAU = 100 sec 1.5x10-11 3x10-11TAU = 1000 sec 5x10-129.5x10-12RF Output Phase Noise (SSB1 Hz <-50 dBc/Hz10 Hz <-70 dBc/Hz 100 Hz <-113 dBc/Hz 1000 Hz <-128 dBc/Hz 10000 Hz <-135 dBc/Hz 100,000 Hz<-140 dBc/HzFrequency Accuracy- Maximum offset at shipment: ±5x10-11- Maximum retrace (48 hrs off: ±5x10-11 - Aging, monthly*: <3x10-10 - Aging, yearly*: <1x10-9 - 1 PPS sync.: ±100 ns(*After 30 days of continuous operationDigital Tuning- Range: ±2x10-8- Resolution: 1x10-12Analog Tuning- Range: ±2.2x10-8 - Resolution: 1x10-11- Input: 0 - 2.5V into 100 kΩWarm-up Time<130 sSolderHand solder using 63/37 Tin/Lead Solder with maximum soldering tip of 329°C (625°FSA.45s CSAC Options 006 and 106Part numbers 090-00218-006 and 090-00218-106. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SpecificationsELECTRICAL SPECIFICATIONSRF Outptut- Frequency: 5 MHz- Format: CMOS - Amplitude: 0V to Vcc- Load impedance: 1 MΩ - Quantity: 11 PPS Output - Rise/fall time (10%-90% at load capacitance 10pF: <10 ns- Pulse width: 400 µs - Level: 0V to Vcc - Logic High (VOH min: 2.80 V - Logic Low (VOL max: 0.30 V - Load impedance:1 MΩ - Quantity: 1 1 PPS Input- Format: Rising edge - Low level: <0.5 V - High level:2.5 V to Vcc - Input impedance: 1 MΩ - Quantity: 1 Serial Communications- Protocol: RS-232 - Format: CMOS 0V to Vcc - Tx/Rx impedance: 1 MΩ - Baud rate: 57600 Built-in Test Equipment (BITE output- Format: CMOS 0V to Vcc - Load impedance: 1 MΩ - Logic: 0 = Normal operation 1 = AlarmPower Input- Operating: <120 mW- Warmup:<140 mW- Input Voltage (Vcc: 3.3 ± 0.1 VDC All specifications at 25°C, Vcc =3.3VDC unless otherwise specifiedPHYSICAL SPECIFICATIONS- Size:1.6” x 1.39” x 0.45” - Weight: <35 g- MTBF:>100,000 hoursENVIRONMENTAL SPECIFICATIONSOperating:- Operating temperature: -10°C to +70°C- Maximum frequency change over operating temp range (max. rate of change0.5°C/minute:5x10-10- Frequency change over allowable input voltage range:<4x10-10- Magnetic sensitivity (≤2.0 Gauss:<9x10-11/Gauss - Radiated emissions: Compliant to FCC part 15, Class B, when mounted properlyonto host PCB- Vibration: Maintains lock under MIL-STD-810, method 514.5, procedure 1,7.7 grms- Humidity: 0 to 95% RH per MIL-STD-810, method 507.4Storage and Transport (non-operating:- Temperature: -55°C to +90°C - Shock (1 ms half-sine: 1000 g - Vibration:M IL-STD-810, method 514.5, procedure 1, 7.7 grmsPERFORMANCE PARAMETERSStability (Allan DeviationADEV -006 -106TAU = 1 sec 1.5x10-10 3x10-10 TAU = 10 sec 5x10-11 9.5x10-11TAU = 100 sec 1.5 x10-11 3 x10-11TAU = 1000 sec 5x10-129.5x10-12RF Output Phase Noise (SSB1 Hz <-53 dBc/Hz10 Hz <-73 dBc/Hz 100 Hz <-116 dBc/Hz 1000 Hz <-131 dBc/Hz 10000 Hz <-138 dBc/Hz 100,000 Hz<-140 dBc/HzFrequency Accuracy- Maximum offset at shipment: ±5x10-11- Maximum retrace (48 hrs off: ±5x10-11 - Aging, monthly*: <3x10-10 - Aging, yearly*: <1x10-9 - 1 PPS sync.: ±100 ns(*After 30 days of continuous operationDigital Tuning- Range: ±2x10-8- Resolution: 1x10-12Analog Tuning- Range: ±2.2x10-8 - Resolution: 1x10-11- Input: 0 - 2.5V into 100 kΩWarm-up Time<130 sSolderHand solder using 63/37 Tin/Lead Solder with maximum soldering tip of 329°C (625°FSA.45s CSAC2300 Orchard ParkwaySan Jose, California 95131-1017 © 2012 Symmetricom. Symmetricom and the Symmetricom logo are registered trademarks of Symmetricom, Inc. All specifications subject to change without notice.。
SA.45s芯片级原子钟
SA.45s芯片级原子钟
产品概述
Symmetricom芯片级原子钟，SA.45s功耗低至 <115 mW，其体积只有<16 cc，提供超低功耗工作模式的设置。
此模式下，其物理封装通常是关闭状态，器件工作于类似TCXO自由振荡的状态，当物理封装定期启动后，重新驯服TCXO（不超过120s），这种模式下的平均功耗不超过50 mW。
第一次让便携仪表也可拥有原子钟水平的准确性及稳定性。
西安同步电子科技有限公司有售
产品功能Array
1)提供一路标准的10MHz正弦信号；
2)同步的1 PPS输入/输出；
3)RS-232管理控制接口。
产品特点
a)超低功耗节电模式，<100 mW；
b)全密闭封装；
c)超小体积，高可靠性。
典型应用
1)水下传感器网络；
2)GPS接收机；
3)背负式电台；
4)反简易爆炸装置(Anti-IED)干扰系统；
5)独立传感器网络无人驾驶飞机等。
技术指标
安装尺寸：。
世界最精准原子钟3亿年误差不到1秒
世界最精准原子钟3亿年误差不到1秒
刘妍
【期刊名称】《今日科苑》
【年(卷),期】2009(000)009
【摘要】美国和丹麦科学家日前联合研制出一款迄今走时最为精确的原子钟。
这种时钟的精度比当前的国际时区校准仪高出2倍以上,每3亿年的误差只有不到1秒。
【总页数】1页(P38)
【作者】刘妍
【作者单位】无
【正文语种】中文
【中图分类】TH714.14
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5.日本专家研制出迄今为止最精准原子钟 [J],
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SA.45s芯片级原子钟
产品概述
Symmetricom芯片级原子钟，SA.45s功耗低至 <115 mW，其体积只有<16 cc，提供超低功耗工作模式的设置。
此模式下，其物理封装通常是关闭状态，器件工作于类似TCXO自由振荡的状态，当物理封装定期启动后，重新驯服TCXO（不超过120s），这种模式下的平均功耗不超过50 mW。
第一次让便携仪表也可拥有原子钟水平的准确性及稳定性。
西安同步电子科技有限公司有售
产品功能Array
1)提供一路标准的10MHz正弦信号；
2)同步的1 PPS输入/输出；
3)RS-232管理控制接口。
产品特点
a)超低功耗节电模式，<100 mW；
b)全密闭封装；
c)超小体积，高可靠性。
典型应用
1)水下传感器网络；
2)GPS接收机；
3)背负式电台；
4)反简易爆炸装置(Anti-IED)干扰系统；
5)独立传感器网络无人驾驶飞机等。
技术指标
安装尺寸：。