The AD7982 is an 18-bit, successive approximation, analog-to- digital converter (ADC) that operates from a single power supply, VDD. It contains a low power, high speed, 18-bit sampling ADC and a versatile serial interface port. On the CNV rising edge, the AD7982 samples the voltage difference between the IN+ and IN− pins. The voltages on these pins usually swing in opposite phases between 0 V and VREF. The reference voltage, REF, is applied externally and can be set independent of the supply voltage, VDD. Its power scales linearly with throughput.
The SPI-compatible serial interface also features the ability, using the SDI input, to daisy-chain several ADCs on a single 3-wire bus and provides an optional busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V, and 5 V logic, using the separate VIO supply.
The AD7982 is available in a 10-lead MSOP or a 10-lead QFN (LFCSP) with operation specified from −40°C to +85°C.
**Applications**
Battery-powered equipment
Data acquisition systems
Medical instruments
Seismic data acquisition systems
### Features and Benefits
18-bit resolution with no missing codes
Throughput: 1 MSPS
Low power dissipation
4 mW at 1 MSPS (VDD only)
7 mW at 1 MSPS (total)
70 μW at 10 kSPS
INL: ±1 LSB typical, ±2 LSB maximum
Dynamic range: 99 dB typical
True differential analog input range: ±VREF
0 V to VREF with VREF between 2.5 V to 5.0 V
Allows use of any input range
Easy to drive with the ADA4941-1 or ADA4940-1
No pipeline delay
Single-supply 2.5 V operation with 1.8 V, 2.5 V, 3 V, and 5 V logic interface
Proprietary serial interface SPI-/QSPI™/ MICROWIRE™-/DSP-compatible
Ability to daisy-chain multiple ADCs and busy indicator
