| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a gate drive circuit capable of reducing a response time to the convergence of a gate voltage to a clamp value, without causing the increase of a circuit area and manufacturing cost. <P>SOLUTION: When abnormality of an overcurrent flow occurs in a transistor Q11, an abnormality detection signal Sa becomes an H level, so that a switch S11 is switched on. In this state, when a potential difference between signal lines L13 and L12 rises to almost exceed a clamp value, a Zener diode D11 breaks down, and the most breakdown current thereof becomes the base current of an amplification transistor T12. A current amplified from the breakdown current by the amplification action of the amplification transistor T12 is supplied to the base of a clamping transistor T11. The clamping transistor T11 produces a collector current flowing between signal lines L11 and L12 in accordance with the supplied base current. By this, a potential difference between the signal lines L11, L12 is decreased. <P>COPYRIGHT: (C)2012,JPO&INPIT |
