MAX31865中文资料_数据手册_参数

VIL
CS, SDI, SCLK
Input Logic 1
Analog Voltages (FORCE+,FORCE2, FORCE-, RTDIN+, RTDIN-) Reference Resistor Cable Resistance
VIH
CS, SDI, SCLK
Normal conversion results
Resolution 0.03125NC (Varies Due to RTD Nonlinearity) S Total Accuracy Over All Operating Conditions: 0.5NC (0.05% of Full Scale) max S ±50V Input Protection S Fully Differential VREF Inputs S Fault Detection (Open RTD Element, RTD Shorted to Out-of-Range Voltage, or Short Across RTD Element) S SPI-Compatible Interface S 20-Pin TQFN Package
2
MAX31865 RTD-to-Digital Converter
ELECTRICAL CHARACTERISTICS (continued)
(3.0V P VDD P 3.6V, TA = -40NC to +125NC, unless otherwise noted. Typical values are TA= +25NC, VDD = VDVDD = 3.3V.) (Notes 2 and 3)
RREF RCABLE
Per lead
MIN 3.0 3.0
-0.3
0.7 x VDVDD
TYP 3.3 3.3
MAX
3.6
3.6
0.3 x VDVDD VDVDD + 0.3
UNITS V V V
V
0
VBIAS
V
350
10k
I
0
50
I
ELECTRICAL CHARACTERISTICS
(3.0V P VDD P 3.6V, TA = -40NC to +125NC, unless otherwise noted. Typical values are TA= +25NC, VDD = VDVDD = 3.3V.) (Notes 2 and 3)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
PARAMETER ADC Resolution ADC Full-Scale Input Voltage (RTDIN+ - RTDIN-)
SYMBOL
CONDITIONS
No missing codes
MIN
TYP MAX UNITS
15
Bits
REFIN+ REFIN-
V
Maxim Integrated
EVALUATION KIT AVAILABLE
MAX31865 RTD-to-Digital Converter
General Description
The MAX31865 is an easy-to-use resistance-to-digital converter optimized for platinum resistance temperature detectors (RTDs). An external resistor sets the sensitivity for the RTD being used and a precision delta-sigma ADC converts the ratio of the RTD resistance to the reference resistance into digital form. The MAX31865’s inputs are protected against overvoltage faults as large as Q50V. Programmable detection of RTD and cable open and short conditions is included.
Applications
Industrial Equipment Medical Equipment Instrumentation
Ordering Information appears at end of data sheet.
For related parts and recommended products to use with this part, refer to www.maximintegrated.com/MAX31865.related.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
TQFN Junction-to-Ambient Thermal Resistance (qJA)...........29°C/W Junction-to-Case Thermal Resistance (qJC)..................2°C/W
Typical Application Circuits
4-WIRE SENSOR CONNECTION VDD
0.1µF
VDD 0.1µF
DVDD VDD
HOST INTERFACE
GND1 GND2 DGND
DRDY SDI SCLK CS SDO N.C.
BIAS REFIN+ REFINISENSOR MAX31865 FORCE+ FORCE2
Features
S Simple Conversion of Platinum RTD Resistance to Digital Value
S Handles 100Ω to 1kΩ (at 0°C) Platinum RTDs (PT100 to PT1000)
S Compatible with 2-, 3-, and 4-wire Sensor Connections S Conversion Time: 21ms max S 15-Bit ADC Resolution; Nominal Temperature
RECOMMENDED DC OPERATING CONDITIONS
(TA = -40NC to +125NC, unless otherwise noted.) (Notes 2 and 3)
PARAMETER
SYMBOL
CONDITIONS
VDD DVDD
VDD VDVDD
Input Logic 0
PARAMETER
SYMBOL源自文库
CONDITIONS
MIN
ADC Common-Mode Input Range
Input Leakage Current
Bias Voltage Bias Voltage Output Current Bias Voltage Load Regulation Bias Voltage Startup Time
Relative to DGND.............................. -0.3V to (VDVDD + 0.3V)
ESD Protection (all pins, Human Body Model)....................±2kV Operating Temperature Range......................... -40NC to +125NC Junction Temperature......................................................+150NC Storage Temperature Range............................. -65NC to +150NC Soldering Temperature (reflow).......................................+260NC Lead Temperature (soldering,10s)..................................+300NC
Continuous Power Dissipation (TA = +70NC) TQFN (derate 34.5mW/NC above +70NC)...............2758.6mW
REFIN-, ISENSOR.................................. -0.3V to (VDD + 0.3V) Voltage Range on FORCE+, FORCE2,
FORCE-, RTDIN+, RTDIN- Relative to GND1.....-50V to +50V Voltage Range on DVDD Relative to DGND.........-0.3V to +4.0V Voltage Range on All Digital Pins
万联芯城www.wlxmall.com专注电子元器件配单服务， 只售原装现货库存，万联芯城电子元器件全国供应，专 为终端生产，研发企业提供现货物料，价格优势明显， BOM配单整单采购可享优惠价，提交BOM表报价，最快 可当天发货，客户整单采购可节约采购时间，节省采购成本， 万联芯城产品体系能够满足多种电子元器件物料需求， 点击进入万联芯城。
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
MAX31865 RTD-to-Digital Converter
ABSOLUTE MAXIMUM RATINGS
Voltage Range on VDD Relative to GND1.............-0.3V to +4.0V Voltage Range on BIAS, REFIN+,
RTDIN+
RTDINFORCE-
RREF
RCABLE
RCABLE
CI*
RTD
RCABLE
RCABLE
*CI = 10nF FOR 1kΩ RTD 100nF FOR 100Ω RTD
Typical Application Circuits continued at end of data sheet.
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-6478; Rev 0; 10/12