ISO6762: Behavior of the VCC1-side output when the VCC2-side power supply is at 0 V

Takayuki Tanaka

Part Number: ISO6762

Tool/software:

I have a question about ISO6762.
If the VCC2 power supply is at 0 V, what happens to the output on the VCC1 side?
If I pull up the VCC1-side output, will it go High, or will it stay Low?

3 months ago

+1 Sara Milliken 3 months ago

TI__Prodigy 120 points

Hi Tanaka-san,
Thanks for reaching out.

Takayuki Tanaka said:
If the VCC2 power supply is at 0 V, what happens to the output on the VCC1 side?

If VCC2 powered off and VCC1 is powered on, the output channels on the VCC1 side will show the default state.

[FAQ] What is the logic state of a digital isolator with no input signal? - Isolation forum - Isolation - TI E2E support forums

Takayuki Tanaka said:
If I pull up the VCC1-side output, will it go High, or will it stay Low?

Assuming VCC1 is still powered on, the state will still match the isolators output state, which would be the default state.

If both VCC1 and VCC2 are powered off, the output state would be undetermined. Considering this, if the output pin has a pull-up when both VCC1 and VCC2 are powered off, then the signal after the pull up would be HIGH.

Best,
Sara