8:1 sensor interface analogue front end

The XR18910 is the latest addition to Exar’s family of analogue front end sensor interfaces. Integrating high channel count and functionality in a 3.5 x 3.5mm package, the device provides 14bit signal path linearity and is designed to connect analogue sensors to MCUs or FPGAs featuring an embedded A/D converter.

The onboard 10bit D/A converter supports ±560mV of offset correction and allows an independent offset value for each of the eight differential inputs. Meanwhile, a programmable gain instrumentation amplifier offers eight fixed gain settings (from 2V/V to 760V/V), ensuring the amplified sensor signal falls within the optimum input range of the downstream A/D converter.

Also featured is an integrated LDO, providing a regulated 3V or 2.65V to power the sensors. The XR18910 is controlled via an I2C serial interface and typically consumes 457µA. A sleep mode reduces the consumption to 45µA.