The AD7981 is a 16-bit, successive approximation, PulSAR^®analog-to-digital converter (ADC) designed for high temperatureoperation. The AD7981 is capable of sample rates of up to 600 kSPSwhile maintaining low power consumption from a single powersupply, VDD. It is a fast throughput, high accuracy, high temperature,successiveapproximation register (SAR) ADC, packaged in asmall form factor with a versatile serial port interface (SPI).

On the CNV rising edge, the AD7981 samples an analog input,IN+, between 0 V and REF with respect to a ground sense, IN−.The reference voltage, REF, is applied externally and can be setindependent of the supply voltage, VDD. The device powerscales 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 compatiblewith 1.8 V, 2.5 V, 3 V, or 5 V logic, using the separate supply, VIO.

For space constrained applications, the AD7981 is available in a10-lead mini small outline package (MSOP) with operation specifiedfrom −55°C to +175°C and 10-lead ceramic flat package(FLATPACK) with operation specified from −55°C to +210°C.These packages are designed for robustness at extreme temperatures,including monometallic wire bonding, and are qualifiedfor up to 1000 hours of operation at the maximum temperaturerating.

The AD7981 is a member of a growing series of high temperaturequalified products offered by Analog Devices, Inc. For a completeselection of available high temperature products, see the hightemperature product list and qualification data available atwww.analog.com/hightemp.

Applications

• Downhole drilling and instrumentation
• Avionics
• Heavy industrial
• High temperature environments

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.