18-Bit, 1.5 LSB INL, 250 KSPS PulSAR® Differential ADC In MSOP/QFN

The AD7691 is an 18-bit, charge redistribution, successive approximation, Analog-to-digital converter (ADC) that operates from a single power supply, VDD, between 2.3 V and 5 V. It contains a low power, high speed, 18-bit sampling ADC with no missing codes, an internal conversion Clock and a versatile serial Interface port. On the CNV rising edge, it samples the voltage difference between the IN+ and IN pins. The voltages on these pins swing in opposite phases between 0 V and REF. The reference voltage, REF, is applied externally and CAN be set up to the supply voltage.
The parts power 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 and provides an optional busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V, or 5 V Logic using the separate VIO supply.
The AD7691 is housed in a 10-lead MSOP or a 10-lead QFN (LFCSP) with operation specified from 40C to +85C.
Applications Battery-powered equipment Data acquisitions Seismic data acquisition systems Instrumentation Medical instruments
Data Sheet, Rev. A, 11/07
By Analog Devices, Inc.