Shunt-Based High Current Measurement (200-A) Reference Design with Reinforced Isolation Amplifier


Design files


This isolated current measurement reference design uses 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 an instrumentation amplifier configuration with a gain of 10 to match the input range of the isolation amplifier for better signal-to-noise ratio. The output of the isolation amplifier is level shifted and scaled to fit the input range of 3.3-V ADCs. This design uses a free running transformer driver operating at 410 kHz for generating isolated supply voltage in a small form factor to power the high voltage side of the circuit.

  • Shunt-based 200-A peak current measurement 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 of -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
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A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Design files & products

Design files

Download ready-to-use system files to speed your design process.


Reference design overview and verified performance test data

TIDRM07.PDF (388 K)

Detailed schematic diagram for design layout and components

TIDRM08.PDF (91 K)

Complete listing of design components, reference designators, and manufacturers/part numbers

TIDRM09.ZIP (159 K)

Detailed overview of design layout for component placement

TIDRM11.ZIP (2110 K)

Files used for 3D models or 2D drawings of IC components

TIDCC86.ZIP (266 K)

Design file that contains information on physical board layer of design PCB

TIDRM10.PDF (720 K)

PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

Isolated amplifiers

AMC1301±250 mV-Input Precision Reinforced Isolated Amplifier for Current Sensing

Data sheet: PDF | HTML
Precision op amps (Vos<1mV)

OPA2376Dual, precision, low-noise, low quiescent current operational amplifier

Data sheet: PDF | HTML
Precision op amps (Vos<1mV)

OPA376Precision (0.025mV), low noise (7.5nV/rtHz), low quiescent current (760uA) op amp

Data sheet: PDF | HTML
Series voltage references

REF20333.3-V Vref, low-drift, low-power, dual-output Vref & Vref/2 voltage reference

Data sheet: PDF | HTML
Shunt voltage references

LM4040-N100-ppm/°C precision micropower shunt voltage reference

Data sheet: PDF
Transformer drivers

SN6501Low-noise, 350-mA, 410-kHz transformer driver for isolated power supplies

Data sheet: PDF | HTML

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Design tools & simulation

Simulation model

TIDA-00912 Simulation (Analog Circuit) — TIDM003.ZIP (110 K)

Simulation model

TIDA-00912 Simulation (Power Supply) — TIDM004.ZIP (105 K)

Technical documentation

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Type Title Date
* Design guide Shunt Based High Current Measurement 200-A Reinforced Amplifier Design Guide (Rev. A) Sep. 21, 2016

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TINA-TI SPICE-based analog simulation program

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