GENERAL DESCRIPTION

The AD7686 is a 16-bit, charge redistribution, successive approximation, analog-to-digital converter (ADC) that operates from a single 5 V power supply, VDD. It contains a low power, high speed, 16-bit sampling ADC with no missing codes, an internal conversion clock, and a versatile serial interface port. The part also contains a low noise, wide bandwidth, short aperture delay track-and-hold circuit. On the CNV rising edge, the AD7686 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. Power dissipation 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 or provides an optional busy indicator. This device is compatible with 1.8 V, 2.5 V, 3 V, or 5 V logic, using the separate supply VIO. The AD7686 is housed in a 10-lead MSOP or a 10-lead QFN (LFCSP) with operation specified from −40°C to +85°C.

FEATURES

16-bit resolution with no missing codes

Throughput: 500 kSPS

INL: ±0.6 LSB typical, ±2 LSB maximum (±0.003 of FSR)

SINAD: 92.5 dB @ 20 kHz

THD: −110 dB @ 20 kHz

Pseudo differential analog input range 0 V to VREFwith VREFup to VDD

No pipeline delay

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

Serial interface SPI®-/QSPI™-/MICROWIRE™-/DSP-compatible

Daisy-chain multiple ADCs and busy indicator

Power dissipation

3.75 μW @ 5 V/100 SPS

3.75 mW @ 5 V/100 kSPS

Standby current: 1 nA

10-lead MSOP (MSOP-8 size) and 3 mm × 3 mm, 10-lead QFN (LFCSP) (SOT-23 size)

Pin-for-pin-compatible with 10-lead MSOP/QFN PulSAR® ADCs

APPLICATIONS

Battery-powered equipment

Data acquisitions

Instrumentation

Medical instruments

Process controls