TPS62180: The PGOOD pin only goes up to 0.56V

user4458706

Part Number: TPS62180

I am using a 12V supply that the enable is connected to. PGOOD is connected to 470K pull-up to output voltage after the inductors. Vout is set be 1.1V. I tested the output for 4A load which was fine but the power good pin doesn't reach the threshold to enable other regulators.

over 8 years ago

0 Juergen over 8 years ago

TI__Expert 5425 points

I guess the pull up resistor value you are using is just to high. At your test condition the current flowing through this resistor is in the range of 1uA. This can be a leakage current in any part of the circuit connected to this PGOOD output.

0 user4458706 over 8 years ago in reply to Juergen

Prodigy 100 points

I tried changing the pull-up to 10K the voltage on PGOOD is now 1.1V which still not high enough to enable the next regulator.

0 Juergen over 8 years ago in reply to user4458706

TI__Expert 5425 points

If the pull up resistor is connected to the 1.1V output of the TPS62180 this is the highest voltage you can get there. If a higher voltage is required you need to connect the pull up resistor to a different voltage rail, for example to the rail supplying the circuit which should be enabled.

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TPS62180: The PGOOD pin only goes up to 0.56V