Bootstrap startup and assist circuit

摘要

A bootstrap assist circuit and a startup circuit comprising a voltage controlled switch and a startup ramp voltage generator connected to the voltage controlled switch that will control a high side switch, a dimming interface or an enable/disable input function. Said system is used to provide a bootstrap technique to continuously switch a floating high side switch (MOSFET) by continuously charging a capacitor and then “level shifting” said capacitor voltage across the gate and source of the said high side switch to turn the switch on.

主权项

1. A method of bootstrap startup comprising:
receiving an input signal to begin bootstrapping; initiating a startup voltage ramp; initiating an artificial ramp current sense; determining if a voltage controlled switch is reverse-biased; and terminating the artificial ramp current sense if the voltage controlled switch is reverse-biased.