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- Shunt Based High Current Measurement 200-A Reinforced Amplifier Design Guide (Rev. A)
(PDF 4374 KB)
21 Sep 2016
The TIDA-00912 TI Design provides a complete reference solution for isolated current measurement using external shunts, reinforced isolation amplifiers, and isolated power supply. The shunt voltage is limited to 25 mV max. This reduces power dissipation in the shunt to enable a high current measurement range up to 200 A. Shunt voltage is amplified by a instrumentation amplifier configuration with a gain of 10 to match the input range of isolation amplifier for better signal to noise ratio. The output of isolation amplifier is level shifted and scaled to fit the complete input range of 3.3-V ADCs. This design uses free running transformer driver operating at 410 kHz for generating isolated supply voltage in a small form factor to power high voltage side of the circuit.
- Shunt-based 200 A peak current measurement solution with reinforced isolation
- Limiting shunt voltage to 25 mV reduces power dissipation
- High-side current sense circuit with high common-mode voltage of 1500-Vpeak, supporting up to 690-V AC mains powered drives
- Calibrated AC accuracy of <1% across temperatures -25oC to 85oC
- Can interface directly with differential or single-ended ADC
- Small form factor push pull-based isolated power supply to power high-side circuit