Single chip shunt monitor boasts 10x accuracy

August 26, 2011 // By Phil Ling
Claiming it to be the most accurate current shunt monitor available today by a factor of 10, Texas Instruments has announced the INA226; a complete 16bit solution in a single chip. It joins TI’s portfolio of current shunt technology and offers current, voltage and power measurements accessed via an I2C interface.

It features a maximum offset voltage of 10uV and a maximum gain error of 0.1%, providing fully programmable measurements for designers working with servers, telecom equipment, computers, power management devices and testing equipment, or wherever accurate power measurements are crucial.

TI says its independently programmable conversion times and sample averaging make it easy to customize to meet the speed requirements of each system, and reduce software and memory requirements. Maximum quiescent current of 420uA and maximum shutdown current of 2uA result in efficient operation that consumes 3.5 percent less power than competitors’ discrete solutions, even with the INA226’s integrated ADC and power mux.

A 140dB common mode rejection ratio (CMRR) and 36V common mode voltage (CMV) help ensure there is little to no change in offset voltage throughout the entire range of operation, simplifying error analysis.

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