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ISO5451: Safety Failure modes

Part Number: ISO5451
Other Parts Discussed in Thread: TIDA-01599, ISO5452


We are working in a safety circuit based on TIDA-01599 reference design. The gate driver in our case is ISO5451 instead ISO5452 of the reference design. From safety point of view, cutting VCC1 power supply will ensure that there is no PWM pulses on the gate driver output?. Can we have info about the failure modes of this element to analyses the failure effects?

Best regards


  • Hi Rober,

    Thank you for posting to E2E.

    Based on the TIDA-01599 and the questions you asked I assume the failure modes you are concerned about are around safe torque off to ensure the gate driver outputs remains LOW (OFF).

    The primary-side(Low voltage) of the gate driver runs off of the VCC1 power supply meaning if there is no VCC1 power supply the gate driver would not be able to communicate across the the isolation barrier to send a HIGH(ON) signal to the secondary-side(High voltage). Keeping VCC1 = 0V (OFF) would ensure that the gate driver output would remain LOW(OFF). In order to ensure VCC1 = 0V you would also have to ensure you follow the rest of the datasheet primary side abs max voltages which specify primary side pins should not have a voltage applied greater that VCC + 0.3V as this could damage the device. If VCC1 = 0V then no voltage should be induced on any of the primary side pins. 

    Best regards,

    Andy Robles

  • Dear Andy,

    Thanks for your reply. Understood.

    Best regards,