GENERAL DESCRIPTION

The AD7903 is a dual 16-bit, successive approximation, analog to-digital converter (ADC) that operates from a single power supply, VDDx, per ADC. It contains two low power, high speed, 16-bit sampling ADCs and a versatile serial port interface (SPI). On the CNVx rising edge, the AD7903 samples the voltage difference between the INx+ and INx− pins. The voltages on these pins usually swing in opposite phases between 0 V and VREF. The externally applied reference voltage of the REFx pins (VREF) can be set independently from the supply voltage pins, VDDx. The power of the device scales linearly with throughput.

Using the SDIx inputs, the SPI-compatible serial interface can also daisy-chain multiple ADCs on a single 3-wire bus and provide an optional busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V, or 5 V logic, using the separate VIOx supplies.

The AD7903 is available in a 20-lead QSOP package with operation specified from −40°C to +125°C.

FEATURES

16-bit resolution with no missing codes

Throughput: 1 MSPS

Low power dissipation

7.0 mW at 1 MSPS (VDD1 and VDD2 only)

12.0 mW at 1 MSPS (total)

140 µW at 10 kSPS

INL: ±0.5 LSB typical, ±2.0 LSB maximum

SINAD: 93.5 dB at 1 kHz

THD: −112 dB at 1 kHz

True differential analog input range: ±VREF

0 V to VREF with VREF between 2.4 V to 5.1 V

Allows use of any input range

Easy to drive with the ADA4941-1

No pipeline delay

Single-supply 2.5 V operation with 1.8 V/2.5 V/3 V/5 V logic

interface

Serial port interface (SPI)/QSPI/MICROWIRE/DSP compatible

20-lead QSOP package

Wide operating temperature range: −40°C to +125°C

APPLICATIONS

Battery-powered equipment

Communications

Automated test equipment (ATE)

Data acquisition

Medical instrumentation

Redundant measurement

Simultaneous sampling

AD7940属于集成电路（IC） > 模数转换器（ADC）。亚德诺半导体技术有限公司制造生产的AD7940模数转换器（ADC）模数转换器（ADC、A/D 或 A 转 D）对模拟信号进行采样，例如由麦克风采集的声音或传感器的输出，然后将其转换为数字信号。一般来说，数字输出是二进制补码二进制数，与输入成比例。输入类型可能是差分、伪差分或单端输入。模数转换器可按照位数、采样率、输入数、接口、转换器数和架构（例如自适应增量、双斜率、折叠、流水线、SAR、三角积分、两步式）进行选择。