Datasheet AD7903 (Analog Devices)

Dual Differential 16-Bit, 1 MSPS PulSAR ADC 12.0 mW in QSOP Data Sheet AD7903 FEATURES GENERAL DESCRIPTION 16-bit resolution with no missing codes
The AD7903 is a dual 16-bit, successive approximation, analog-
Throughput: 1 MSPS
to-digital converter (ADC) that operates from a single power
Low power dissipation
supply, VDDx, per ADC. It contains two low power, high speed,
7.0 mW at 1 MSPS (VDD1 and VDD2 only)
16-bit sampling ADCs and a versatile serial port interface (SPI).
12.0 mW at 1 MSPS (total)
On the CNVx rising edge, the AD7903 samples the voltage
140 µW at 10 kSPS
difference between the INx+ and INx− pins. The voltages on
INL: ±0.5 LSB typical, ±2.0 LSB maximum
these pins usually swing in opposite phases between 0 V and
SINAD: 93.5 dB at 1 kHz
VREF. The external y applied reference voltage of the REFx pins
THD: −112 dB at 1 kHz
(VREF) can be set independently from the supply voltage pins,
True differential analog input range: ±VREF
VDDx. The power of the device scales linearly with throughput.
0 V to VREF with VREF between 2.4 V to 5.1 V
Using the SDIx inputs, the SPI-compatible serial interface can
Allows use of any input range
also daisy-chain multiple ADCs on a single 3-wire bus and provide
Easy to drive with the ADA4941-1
an optional busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V,
No pipeline delay
or 5 V logic, using the separate VIOx supplies.
Single-supply 2.5 V operation with 1.8 V/2.5 V/3 V/5 V logic interface
The AD7903 is available in a 20-lead QSOP package with operation
Serial port interface (SPI)/QSPI/MICROWIRE/DSP compatible
specified from −40°C to +125°C.
20-lead QSOP package Table 1. MSOP 14-/16-/18-Bit PulSAR® ADCs Wide operating temperature range: −40°C to +125°C 100 250 400 kSPS 1000 ADC APPLICATIONS Bits kSPS kSPS to 500 kSPS kSPS Driver
18 AD76911 AD76901 AD79821 ADA4941-1
Battery-powered equipment
ADA4841-x
Communications
16 AD7680 AD76851 AD76861 AD79801 ADA4941-1
Automated test equipment (ATE)
AD7683 AD76871 AD76881 AD7903 ADA4841-x
Data acquisition
AD7684 AD7694 AD76931 AD7902
Medical instrumentation
14 AD7940 AD79421 AD79461
Redundant measurement
1 Pin-for-pin compatible.
Simultaneous sampling FUNCTIONAL BLOCK DIAGRAM REF = 2.5V TO 5V 2.5V REF1 REF2 VDD1 VDD2 ADA4941-1 VIO1 VIO1/VIO2 REF IN1+ SDI1 SDI1/SDI2 ADC1 SCK1 SCK1/SCK2 CNV1 CNV1/CNV2 ±10V, ±5V, ... IN1– SDO1 SDO1 ADA4941-1 VIO2 REF IN2+ 3-WIRE OR 4-WIRE SDI2 INTERFACE ADC2 SCK2 (SPI, CS, AND CHAIN MODES) CNV2 ±10V, ±5V, ... IN2– SDO2 SDO2 GND AD7903
001 11755- Figure 1.
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Document Outline Features Applications General Description Functional Block Diagram Table of Contents Revision History Specifications Timing Specifications Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Terminology Theory of Operation Circuit Information Converter Operation Transfer Functions Typical Connection Diagram Analog Inputs Driver Amplifier Choice Single-to-Differential Driver Voltage Reference Input Power Supply Digital Interface CS Mode CS Mode, 3-Wire Interface Without Busy Indicator CS Mode, 3-Wire Interface with Busy Indicator CS Mode, 4-Wire Interface Without Busy Indicator CS Mode, 4-Wire Interface with Busy Indicator Chain Mode Chain Mode Without Busy Indicator Chain Mode with Busy Indicator Applications Information Simultaneous Sampling Functional Safety Considerations Layout Evaluating Performance of the AD7903 Outline Dimensions Ordering Guide