• 1 Post
  • 985 Comments
Joined 1 year ago
cake
Cake day: June 12th, 2023

help-circle
  • The charge pump not being stable can mean several things. If it’s not where it should be (it won’t be) the high side fets won’t turn on all the way, causing loads of excess heat inside the chip. This also may never recover, depending on the duty cycle, and then that chip will burn up/let the smoke out.

    Essentially, the charge pump capacitor has a set of circuitry that brings the low side of it low, lets it get 5 or 12v, then floats it up to the voltage rail, to turn on the fet hard. If it’s only partially on, the fet has a resistance that is too high. (The high side of the capacitor usually has a diode to charge it)