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LT8610AB PGOOD de-bounce capacitor


We are using the LT8610AB as a primary 5V regulator with its PG open-drain output used to enable/disable downstream regulators. This is done via a 100kOhm pull-up resistor (R2) to the regulators 5V output.

During testing we have found that the addition of a 470nF ceramic capacitor (C3) effectively helps prevent any nuisance PG resets caused by glitches that may appear on the 5V rail.

So I am wondering if this is acceptable considering that there are no maximum energy limits specified in the datasheet for the PGOOD open-drain?


  • The above circuit will sink (1/2*C*V^2) = ~5.9 uJ into PG. Duty cycle will be very low.
  • Other low drain current nmos transistors typically specify max drain ratings at 3A for 300us (or 900uC) (e.g. which is significantly higher than 5.9 uJ

Thanks for any updates.

  • Reviewing further on the forum I notice a similar regulator IC (LTM4622) which has a max sink current of 10mA  LTM4622- PGOOD Sink Current capability 

    The LT8610AB is specified with a PG Pull-Down resistance of typ 680Ohms, max 2kOhms (pg 4 of the datasheet), which means for the lower case of 680Ohms, max instantaneous current sunk by PG in the above circuit will be 5/680 = 7.35mA.

    As this is lower than 10mA it would seem acceptable however this assumes that the LT8610AB has the same max PG pull down rating as the LTM4622.

    Please confirm, thank again for any updates.

  • Hi,

    Thanks for the information and application of LT8610.

    Yes, the current rating is close to that level. The PG pull-down resistor limits the current flowing through the PG internal transistor. 

    The 470nF cap at PG pin should be good.

    Best regards,