GENERAL DESCRIPTION

The AD7694 is a 16-bit, charge redistribution, successive approximation, PulSAR analog-to-digital converter (ADC) that operates from a single power supply, VDD, between 2.7 V to 5.25 V. It contains a low power, high speed, 16-bit sampling ADC with no missing codes (B grade), an internal conversion clock, and a serial, SPI-compatible interface port. The part also contains a low noise, wide bandwidth, short aperture delay track-and-hold circuit. On the CNV rising edge, it samples an analog input, IN+, between 0 V to REF with respect to a ground sense, IN?. The reference voltage, REF, is applied externally and can be set up to the supply voltage.

FEATURES

16-bit resolution with no missing codes

Throughput: 250 kSPS at 5 V

INL: ±4 LSB max

S/(N + D): 92 dB at 20 kHz

THD: –106 dB at 20 kHz

Pseudo-differential analog input range:

0 V to VREF with VREF up to VDD

No pipeline delay

Single-supply operation: 2.7 V or 5 V

Proprietary serial interface

SPI?-/QSPI?-/MICROWIRE?-/DSP-compatible1

Supply Current: 540 μA at 2.7 V/100 kSPS,

800 μA at 5 V/100 kSPS

Standby current: 1 nA

8-lead MSOP package

Improved second source to LTC1864 and LTC1864L

APPLICATIONS

Battery-powered equipment

Data acquisition

Instrumentation

Medical instruments

Process control