GENERAL DESCRIPTION

The AD79851 is a 16-bit, 2.5 MSPS successive approximation analog-to-digital converter (SAR ADC). It contains a low power, high speed, 16-bit sampling ADC, an internal conversion clock, an internal reference (and buffer), error correction circuits, and a versatile serial interface port. On the rising edge of CNV, the AD7985 samples an analog input, IN+, between 0 V and REF with respect to a ground sense, IN−. The AD7985 features a very high sampling rate turbo mode (TURBO is high) and a reduced power normal mode (TURBO is low) for low power applications where the power is scaled with the throughput.

FEATURES

16-bit resolution with no missing codes

Throughput: 2.5 MSPS (TURBO high), 2.0 MSPS (TURBO low)

Low power dissipation

15.5 mW at 2.5 MSPS, with external reference

28 mW at 2.5 MSPS, with internal reference

INL: ±0.7 LSB typical, ±1.5 LSB maximum

SNR

88.5 dB, with on-chip reference

90 dB, with external reference

4.096 V internal reference: typical drift of ±10 ppm/°C

Pseudo differential analog input voltage range

0 V to VREF with VREF up to 5.0 V

Allows use of any input range

No pipeline delay

Logic interface: 1.8 V/2.5 V/2.7 V

Proprietary serial interface SPI-/QSPI™-/MICROWIRE™-/DSP-compatible1

Ability to daisy-chain multiple ADCs with busy indicator

20-lead, 4 mm × 4 mm LFCSP

APPLICATIONS

Battery-powered equipment

Communications

ATE

Data acquisition systems

Medical instruments