Synchronous buck converter circuit i.e. direct current/direct current conversion circuit, for converting high direct current voltage to low direct current voltage in voltage conversion circuit, has protection circuitry disabling conduction

摘要

The circuit has a control circuitry (106) controlling a duty cycle of a depletion-mode III-nitride control switch (102). A depletion-mode III-nitride synchronous switch (104) is interposed between an output and ground, where the control switch and the synchronous switch have a pair of depletion-mode III-nitride transistors (Q1, Q2) e.g. depletion-mode gallium nitride high electron mobility transistors. A protection circuitry (110) disables current conduction through the control switch when the control circuitry is not powered up.