XR18910 8:1 Sensor Interface AFE
The XR18910 is a unique sensor interface integrated circuit with an on-board 8:1 multiplexer, offset correction DAC, instrumentation amplifier and voltage reference. The XR18910 is designed to integrate multiple bridge sensors with a Microcontroller (MCU) or Field Programmable Gate Array (FPGA).
The integrated offset correction DAC provides digital calibration of the variable and in many cases substantial offset voltage generated by the bridge sensors. The DAC is controlled by an I2C compatible two-wire serial interface. The serial interface also provides the user with easy controls to the XR18910’s many functions such as input and gain selection.
An integrated LDO provides a regulated voltage to power the input bridge sensors and is selectable, between 3V and 2.65V, via the serial interface for lower voltage compatibility. The LDO current can be sensed and a proportional voltage present at the output of the IC for monitoring the LDO current.
The XR18910 offers eight fixed gain settings (from 2V/V to 760V/V), each with an error of only ±0.5%, that are selectable via the I2C interface. The XR18910 is designed to operate from 2.7V to 5V supplies and is specified over the industrial temperature range of -40°C to 85°C. It is offered in a space saving 3.5mm x 3.5mm QFN-24 package. It consumes less than 559μA maximum supply current and offers a sleep mode for added power savings.
- Integrated features for interfacing multiple bridge sensors with an MCU or FPGA: 8:1 differential mux with I2C interface Instrumentation amplifier LDO Offset correction DAC with I2C interface (±560mV offset correction range - RTI)
- Eight selectable voltage gains from 2V/V to 760V/V with only ±0.5% gain error
- 3mV maximum input offset voltage
- 100pA maximum input bias current 559μA maximum supply current
- 2.7V to 5V analog supply voltage range
- 1.8V to 5V digital supply voltage range
- 40˚C to 85˚C temperature range
- 3.5 x 3.5mm QFN-24
Exar Corporation designs, develops and markets high performance integrated circuits and system solutions for the industrial and embedded systems communications, high end consumer and infrastructure markets. Exar's broad product portfolio includes power management, sensing and signal conditioning, interface, display, LED lighting and video processing solutions.
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