buenos
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There is a feature that some of the DC/DC converters have, that is to discharge the output capacitors (by the lower mosfet) when the converter is not enabled (by the enable input pin). The most common step down DC/DC (buck) converter architecture is called "synchronous rectifier", this basically has an upper mosfet (drives to VDD) and a lower mosfet (drives to GND) connected to the output inductor. The lower of the 2 mosfets is utilized by some controllers to short the output to ground before the enable is asserted (before turn on event), and after the enable is de-asserted (after a turn off event).
Some controllers seem to have this feature, while others don't. I can tell when the basic controller is turned off, its output voltage slowly decays, instead of shutting off, some cases even worse the output decays to a plateau, stays there, then decays further. The intermediate voltage can cause digital chips to malfunction, so a decisive shutdown is preferred. It can fool reset generators to de-assert an internal reset signal before VCC would become stable enough.
Years ago I saw this described in detail in a DCDC controller chip datasheet. Today I looked at some datasheets and I found no reference to whether they have it or not.
So, my question is: what is this feature called? How to find out about each new DCDC chip datasheet whether they have this feature or not.
Some controllers seem to have this feature, while others don't. I can tell when the basic controller is turned off, its output voltage slowly decays, instead of shutting off, some cases even worse the output decays to a plateau, stays there, then decays further. The intermediate voltage can cause digital chips to malfunction, so a decisive shutdown is preferred. It can fool reset generators to de-assert an internal reset signal before VCC would become stable enough.
Years ago I saw this described in detail in a DCDC controller chip datasheet. Today I looked at some datasheets and I found no reference to whether they have it or not.
So, my question is: what is this feature called? How to find out about each new DCDC chip datasheet whether they have this feature or not.