a Low Noise, High Throughput
24-Bit Sigma-Delta ADC
AD7731
GENERAL DESCRIPTION FEATURES
24-Bit Sigma-Delta ADC
16 Bits p-p Resolution at 800 Hz Output Rate
Programmable Output Rates up to 6.4 kHz
Programmable Gain Front End
60.0015% Nonlinearity
Buffered Differential Inputs
Programmable Filter Cutoffs
FASTStep™* Mode for Channel Sequencing
Single Supply Operation The AD7731 is a complete analog front-end for process control
applications. The device has a proprietary programmable gain
front end that allows it to accept a range of input signal ranges,
including low level signals, directly from a transducer. The sigmadelta architecture of the part consists of an analog modulator
and a low pass programmable digital filter, allowing adjustment
of filter cutoff, output rate and settling time.
The part features three buffered differential programmable gain
analog inputs (which can be configured as five pseudo-differential
inputs), as well as a differential reference input. The part operates from a single +5 V supply and accepts seven unipolar analog input ranges: 0 to +20 mV, +40 mV, +80 mV, +160 mV,
+320 mV, +640 mV and +1.28 V, and seven bipolar ranges:
± 20 mV, ± 40 mV, ± 80 mV, ± 160 mV, ± 320 mV, ± 640 mV and …