
Analog Devices
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