AD7797

www.DataSheet4U.com Low Power, 16-/24-Bit Sigma-Delta ADC for Bridge Sensors AD7796/AD7797 FEATURES RMS noise: 65 nV Instrumentation amp Temperature sensor Internal clock oscillator Simultaneous 50 Hz/60 Hz rejection Update rate: 4.17 Hz to 123 Hz Current: 250 μA typ Power-down: 1 μA Power supply: 2.7 V to 5.25 V –40°C to +85°C temperature range Independent interface power supply 16-lead TSSOP GENERAL DESCRIPTION The AD7796/AD7797 are complete, analog front ends for high precision, bridge sensor applications such as weigh scales. The AD7796/AD7797 contain a Σ-Δ ADC capable of 16-/24-bit resolution, respectively. The on-chip instrumentation amplifier has a fixed gain of 128, allowing small amplitude signals such as those from bridge sensors to be directly interfaced to the ADC. Each part has one differential input and contains a temperature sensor that is internally connected to the ADC. This sensor can be used to perform temperature compensation of the bridge. The devices can be operated with the internal clock or an external clock. The output data rate from the parts is softwareprogrammable and can be varied from 4.17 Hz to 123 Hz. The AD7796/AD7797 operate with a power supply from 2.7 V to 5.25 V. Each part consumes a current of 250 μA typical and is housed in a 16-lead TSSOP. INTERFACE 3-wire serial SPI®, QSPI™, MICROWIRE™, and DSP compatible Schmitt trigger on SCLK APPLICATIONS Weigh scales Strain gages Industrial process control Instrumentation Portable instrumentati...