Shunt-Based 200A Peak Current Measurement Reference Design Using Isolation Amplifier
TIDA-00445
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Key Document
- Shunt Based 200A Peak Current Measurement Using Isolation Amplifier Design Guide (Rev. A)
(PDF 2056 KB)
05 Mar 2016
Description
The TIDA-00445 TI design provides a reference solution for isolated current measurement using shunt and isolated amplifier. By limiting the shunt voltage to 25mV, this design is able to reduce power dissipation in the shunt and achieves a high current measurement range of up to 200A. Shunt voltage is further amplified by precision Opamps in instrumentation amplifier based configuration with a gain of 10 to match the input range of isolation amplifier. The output of isolation amplifier is level shifted and scaled to utilize the complete input range of 3.3v ADC. This design uses free running transformer driver for generating isolated supply voltage for the high voltage side of the circuit. Small form factor for the power supply is achieved by the operation of driver at 400 KHz.
Features
- Shunt based isolated 200Apk current measurement solution
- Limiting shunt voltage to 25mV helps achieving less power dissipation
- High-Side Current Sense Circuit With High Common Mode Voltage of 1200 V peak Supporting up to 690V AC Mains Powered Drives
- Calibrated AC accuracy of <1% across temperatures -25˚c to +85˚c
- Can be Interfaced directly with differential or single ended ADC
- Small form factor push pull based isolated power supply to power high side circuit
- Inbuilt 1.65VREF for level shifting the output.
See the Important Notice and Disclaimer covering reference designs and other TI resources.