Gate driver and semiconductor device employing the same
A gate driver for driving a gate of a switching element Tr 7 includes a driving part that drives the switching element according to a control signal and an active clamp circuit to clamp the voltage between the first and second main terminals of the switching element through the driving part. If a voltage applied between a first main terminal (drain) and a second main terminal (source) of the switching element exceeds a predetermined voltage, the active clamp circuit forcibly blocks a driving operation of the driving part from driving the switching element.
1. A gate driver for driving a gate of a switching element, comprising:
a driving part configured to drive the switching element according to a control signal; and
an active clamp circuit configured to clamp the voltage between the first and second main terminals of the switching element through the driving part, the active clamp circuit including
a first transistor configured to drive the switching element so that the voltage between the first and second main terminals of the switching element is clamped
a second transistor configured to block a driving transistor of the driving part from turning on for switching off the switching element during the clamping operation of the active clamp circuit, wherein
if a voltage applied between first and second main terminals of the switching element exceeds a predetermined voltage, the active clamp circuit forcibly blocks a driving operation of the driving part from switching off the switching element.
2. The gate driver of claim 1 wherein the switching element is a GaN High-Electron-Mobility-Transistor (HEMT).
3. A semiconductor device connected between terminals of a DC power source through a load and configured to control a current passing through the load, comprising:
a second switching element connected in series to the DC power source and the load; and
the gate driver according to claim 1 .
4. The semiconductor device of claim 3 wherein the first or second switching element is a GaN High-Electron-Mobility-Transistor (HEMT).