AD7785

3-Channel, Low Noise, Low Power, 20-Bit ∑-Δ ADC with On-Chip In-Amp and Reference AD7785 FEATURES Up to 20 bits effective resolution RMS noise 40 nV @ 4.17 Hz 85 nV @ 16.7 Hz Current: 400 μA typical Power-down: 1 μA maximum Low noise programmable gain instrumentation amp Band gap reference with 4 ppm/°C drift typical Update rate: 4.17 Hz to 470 Hz 3 differential inputs Internal clock oscillator Simultaneous 50 Hz/60 Hz rejection Programmable current sources On-chip bias voltage generator Burnout currents Power supply: 2.7 V to 5.25 V –40°C to +105°C temperature range Independent interface power supply 16-lead TSSOP package Interface www.DataSheet4U.com 3-wire serial SPI®, QSPI™, MICROWIRE™, and DSP compatible Schmitt trigger on SCLK Industrial process control Instrumentation Portable instrumentation Blood analysis Smart transmitters Liquid/gas chromatography 6-digit DVM GENERAL DESCRIPTION The AD7785 is a low power, low noise, complete analog front end for high precision measurement applications. The AD7785 contains a low noise 20-bit ∑-Δ ADC with three differential analog inputs. 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 40 nV when the update rate equals 4.17 Hz. 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 ...