8:1 Sensor Interface Analog Front End Simplifies Sensor Conditioning

Exar XR18910

Exar Corporation announces the XR18910, the latest addition to its family of analog front end sensor interfaces, which integrates high channel count and functionality in a tiny 3.5 mm × 3.5 mm footprint. The XR18910 provides 14-bit signal path linearity and is designed to connect analog sensors to a microcontroller (MCU) or field-programmable gate array (FPGA) with an embedded ADC.

Exar - XR18910

The onboard 10-bit DAC offers ±560 mV of offset correction and allows an independent offset value for each of the eight differential inputs. The programmable gain instrumentation amplifier offers eight fixed-gain settings (from 2 V/V to 760 V/V), ensuring the amplified sensor signal falls within the optimum input range of the downstream ADC. The integrated LDO provides a regulated 3 V or 2.65 V voltage to power the sensors. The XR18910 is controlled via an I2C serial interface and typically consumes 457 µA of supply current and offers a sleep mode which reduces the supply current to only 45 µA.

Typical Application Circuit
Typical Application Circuit.

"The XR18910 provides designers with an easy-to-use sensor interface that calibrates and amplifies signals from eight different analog sensors, improving overall system sensitivity and accuracy," said Dale Wedel, vice president of high performance analog. "It offers more functionality with lower power than discrete solutions and is suitable for a variety of applications such as force sensing, pod racers and power monitoring for solar energy and data centers. It also occupies a significantly smaller footprint than our original XR10910 16:1 sensor interface, making it more attractive when fewer channels are required."

The XR18910 is available in a RoHS compliant, green/halogen free, space-saving 3.5 mm × 3.5 mm QFN package. The XR18910 is priced at $6.10 in 1,000-piece quantities.