GENERAL DESCRIPTION

The AD7946 is a 14-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, 14-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, 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

14-bit resolution with no missing codes

Throughput: 500 kSPS

INL: ±0.4 LSB typical, ±1 LSB maximum (±0.0061% of FSR)

SINAD: 85 dB @ 20 kHz

THD: −100 dB @ 20 kHz

Pseudo differential analog input range

   0 V to REF with REF up 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

   3.3 mW @ 5 V/100 kSPS

   3.3 μW @ 5 V/100 SPS

Standby current: 1 nA

10-lead MSOP (MSOP-8 size) and

   3 mm × 3 mm QFN (LFCSP) (SOT-23 size)

Pin-for-pin compatible with the 16-bit AD7686

APPLICATIONS

Battery-powered equipment

Data acquisition

Instrumentation

Medical instruments

Process control