LM7480-Q1: LM7480 - overvoltage recovery

Andres Sanchez Gonzalez

Part Number: LM7480-Q1
Other Parts Discussed in Thread: LM7480

Hello,

I am developing a that incorporates the LM7480 in common‑drain configuration.
I am validating the design on the LM7480 evaluation board.

The over‑voltage (OV) resistor network has been sized correctly according to the datasheet recommendations.
However, I am unable to locate the formula needed to calculate the resistor values for the over-voltage recovery circuit.

Thanks,
Andrés

4 months ago

0 Shiven Dhir 4 months ago

TI__Guru 62370 points

Hi Andres,

If you are using 3 resistor configuration, please find the formula below.

If you are using only 2, then a normal resistor divider is fine.

Regards,

Shiven Dhir

0 Andres Sanchez Gonzalez 4 months ago in reply to Shiven Dhir

Prodigy 20 points

HI Shiven,

Thanks for the prompt answer.

That's the formula used to calculate the overvoltage protection threshold. I'm looking for the formula used to calculate the value of the recovery voltage after an overvoltage event (what is the minimum voltage needed by the LM74801 to reactivate the output).

Regards,
Andrés

0 Shiven Dhir 4 months ago in reply to Andres Sanchez Gonzalez

TI__Guru 62370 points

Ah I see, for that case just change the value of V_OVR to V_OVF

Regards,

Shiven Dhir

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LM7480-Q1: LM7480 - overvoltage recovery