Application Circuit (Current sensing) of the TLP7920 Isolation Amplifier

This reference design provides design guide and example of simulation waveform for phase current detection with optical isolation amplifier for motor control of servo and inverter.

Application block diagram of application circuit (current sensing) of the TLP7920 isolation amplifier.
Application Block Diagram
Applicatoin Circuit Diagram of application circuit (current sensing) of the TLP7920 isolation amplifier.
Applicatoin Circuit Diagram


  • Description of TLP7920 signature functions and features, especially common mode transient immunity, nonlenearity feature and low cosumption current
  • Design guide for the typical application circuit, current sensing circuit
  • Operation confirmation by Spice simulation


  • Optically coupled isolation amplifier
  • Common mode noise imunity : 15kV/μs(Min)
  • Low comsumption current : Primary side 8.6mA(typ.), Secondary side 6.2mA(typ.)

Reference design files

Design, Document

“Design・Document” contains the documents listed below.

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Design, File

“Design・File” contains the contents listed below.

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Toshiba items

Part Number Device Category Portion Usage Description
TLP7920 Isolation amplifier signal amplifier・1 Isolation amplifier/Analog output/DIP8


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