The AD7785BRUZ is a 3-channel low noise, low power 20-bit sigma-delta Analog-to-digital Converter (ADC) with on-chip in-amp and reference. It is a complete analog front end for high precision measurement applications. The on-chip low noise instrumentation amplifier means that signals of small amplitude can be interfaced directly to the ADC. With a gain setting of 64 the rms noise is 40nV when the update rate equals 4.17Hz. The device contains a precision low noise, low drift internal band gap reference and can accept an external differential reference. Other on-chip features include programmable excitation current sources, burnout currents and a bias voltage generator. The bias voltage generator sets the common-mode voltage of a channel to AVDD/2. It can be operated with either the internal clock or an external clock.
Low noise programmable gain instrumentation amp
Band gap reference with 4ppm/°C drift typical
Internal clock oscillator
Programmable current sources
On-chip bias voltage generator
Burnout currents
Independent interface power supply
3-wire serial SPI®/QSPI™/MICROWIRE™/DSP compatible Schmitt trigger on SCLK
