AD7195

4.8 kHz, Ultralow Noise, 24-Bit Sigma-Delta ADC with PGA and AC Excitation AD7195 www.DataSheet4U.com FEATURES AC or DC sensor excitation RMS noise: 8.5 nV at 4.7 Hz (gain = 128) 16 noise-free bits at 2.4 kHz (gain = 128) Up to 22.5 noise-free bits (gain = 1) Offset drift: 5 nV/°C Gain drift: 1 ppm/°C Specified drift over time 2 differential/4 pseudo differential input channels Automatic channel sequencer Programmable gain (1 to 128) Output data rate: 4.7 Hz to 4.8 kHz Internal or external clock Simultaneous 50 Hz/60 Hz rejection Power supply AVDD: 4.75 V to 5.25 V DVDD: 2.7 V to 5.25 V Current: 6 mA Temperature range: –40°C to +105°C Package: 32-lead LFCSP Chromatography PLC/DCS analog input modules Data acquisition Medical and scientific instrumentation GENERAL DESCRIPTION The AD7195 is a low noise, complete analog front end for high precision measurement applications. It contains a low noise, 24-bit sigma-delta (Σ-Δ) analog-to-digital converter (ADC). The on-chip low noise gain stage means that signals of small amplitude can be interfaced directly to the ADC. The AD7195 contains ac excitation, which is used to remove dc-induced offsets from bridge sensors. The device can be configured to have two differential inputs or four pseudo differential inputs. The on-chip channel sequencer allows several channels to be enabled, and the AD7195 sequentially converts on each enabled channel. This simplifies communication with the part. The on-chip 4.92 MHz clock can be used as the ...