AD7851资料

SM2
SYNC
DIN
DOUT SCLK POLARITY
PRODUCT HIGHLIGHTS
The AD7851 is a high speed, 14-bit ADC that operates from a single 5 V power supply. The ADC powers-up with a set of default conditions at which time it can be operated as a readonly ADC. The ADC contains self-calibration and systemcalibration options to ensure accurate operation over time and temperature and has a number of power-down options for low power applications. The AD7851 is capable of 333 kHz throughput rate. The input track-and-hold acquires a signal in 0.33 µs and features a pseudo-differential sampling scheme. The AD7851 has the added advantage of two input voltage ranges (0 V to VREF, and –VREF/2 to +VREF/2 centered about VREF/2). Input signal range is to VDD and the part is capable of converting full-power signals to 20 MHz. CMOS construction ensures low power dissipation (60 mW typ) with power-down mode (5 µW typ). The part is available in 24pin, 0.3 inch-wide dual-in-line package (DIP), 24-lead small outline (SOIC) and 24-lead small shrink outline (SSOP) packages.
A1 77 –86 –87 –86 –86 20 14 ±2 ±2 ± 10 ± 10 ± 10 ±1
K1 78 –86 –87 –90 –90 20 14 ±1 ±1 ± 10 ± 10 ± 10 ±1
Units dB min dB max dB max dB typ dB typ MHz typ Bits LSB max LSB max LSB max LSB max LSB typ LSB typ Volts Volts µA max pF typ V min/max kΩ typ V min/max ppm/°C typ V min V max µA max pF max V min V max µA max pF max
*Patent pending. See Page 35 for data sheet index.
1. 2. 3. 4. 5.
Single 5 V supply. Operates with reference voltages from 4 V to VDD. Analog input ranges from 0 V to VDD. System and self-calibration including power-down mode. Versatile serial I/O port.
REV. A
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. © Analog Devices, Inc., 1996 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 617/329-4700 Fax: 617/326-8703
AIN (+) T/H AIN (–)
14-Bit 333 kSPS Serial A/D Converter AD7851
FUNCTIONAL BLOCK DIAGRAM
AVDD AGND AGND DVDD
AD7851
4.096 V REFERENCE
DGND
REFIN/ REFOUT
BUF
COMP AMODE
CREF1
CHARGE REDISTRIBUTION DAC
CLKIN SAR + ADC CONTROL CONVST BUSY SLEEP
CREF2 CALIBRATION MEMORY AND CONTROLLER
CAL
SERIAL INTERFACE / CONTROL REGISTER
SM1
i.e., AIN(+) – AIN(–) = 0 V to VREF, AIN(–) can be biased up but AIN(+) cannot go below AIN(–). i.e., AIN(+) – AIN(–) = –VREF/2 to +VREF/2, AIN(–) should be biased up and AIN(+) can go below AIN(–) but cannot go below 0 V.
元器件交易网
1, 2 (0؇C to +85؇C), f = 285 kHz; A and K Grade: f = 5 MHz (to +125؇C), f = AD7851–SPECIFICATIONS 238 kHz; (AV = DV = +5.0 V ؎ 5%, REF /REF = 4.096 V External Reference; SLEEP = Logic High; T = T to T , unless otherwise noted)
SAMPLE CLKIN SAMPLE DD DD IN OUT A MIN MAX
A Grade: fCLKIN = 7 MHz (–40؇C to +85؇C), fSAMPLE = 333 kHz; K Grade: fCLKIN = 6 MHz
Parameter DYNAMIC PERFORMANCE Signal-to-Noise + Distortion Ratio3 (SNR) Total Harmonic Distortion (THD) Peak Harmonic or Spurious Noise Intermodulation Distortion (IMD) Second Order Terms Third Order Terms Full Power Bandwidth DC ACCURACY Resolution Integral Nonlinearity Differential Nonlinearity Unipolar Offset Error Positive Full-Scale Error Negative Full-Scale Error Bipolar Zero Error ANALOG INPUT Input Voltage Ranges
Test Conditions/Comments Typically SNR is 79.5 dB VIN = 10 kHz, Sine Wave, fSAMPLE = 333 kHz VIN = 10 kHz, Sine Wave, fSAMPLE = 333 kHz, Typically –96 dB VIN = 10 kHz, fSAMPLE = 333 kHz fa = 9.983 kHz, fb = 10.05 kHz, fSAMPLE = 333 kHz fa = 9.983 kHz, fb = 10.05 kHz, fSAMPLE = 333 kHz @ 3 dB
Leakage Current Input Capacitance REFERENCE INPUT/OUTPUT REFIN Input Voltage Range Input Impedance REFOUT Output Voltage REFOUT Tempco LOGIC INPUTS Input High Voltage, VINH Input Low Voltage, VINL Input Current, IIN Input Capacitance, CIN5 LOGIC OUTPUTS Output High Voltage, VOH Output Low Voltage, VOL Floating-State Leakage Current Floating-State Output Capacitance 5 Output Coding CONVERSION RATE Conversion Time Conversion + T/H AcquisitionTURES Single 5 V Supply 333 kSPS Throughput Rate/ ؎2 LSB DNL—A Grade 285 kSPS Throughput Rate/ ؎1 LSB DNL—K Grade A & K Grades Guaranteed to 125؇ C/238 kSPS Throughput Rate Pseudo-Differential Input with Two Input Ranges System and Self-Calibration with Autocalibration on Power-Up Read/Write Capability of Calibration Data Low Power: 60 mW typ Power-Down Mode: 5 ␮W typ Power Consumption Flexible Serial Interface: 8051/SPI/QSPI/ ␮ P Compatible 24-Pin DIP, SOIC and SSOP Packages APPLICATIONS Digital Signal Processing Speech Recognition and Synthesis Spectrum Analysis DSP Servo Control Instrumentation and Control Systems High Speed Modems Automotive GENERAL DESCRIPTION
Guaranteed No Missed Codes to 14 Bits Review: “Adjusting the Offset Calibration Register” in the “Calibration Registers” section of the data sheet.
0 V to VREF 0 V to VREF ± VREF/2 ±1 20 4/VDD 150 3.696/4.496 50 VDD – 1.0 0.4 ± 10 10 ± VREF/2 ±1 20 4/VDD 150 3.696/4.496 50 VDD – 1.0 0.4 ± 10 10