DRIVE CIRCUIT OF HIGH-SIDE TRANSISTOR, CONTROL CIRCUIT OF DC/DC CONVERTER ARRANGED BY USE THEREOF, AND DC/DC CONVERTER

摘要

To provide a drive circuit capable of setting a high-side transistor to OFF in the event of abnormality.SOLUTION: A drive circuit 400 drives an N channel or NPN-type high-side transistor 302. The drive circuit comprises: a level shift circuit 410 including an open-drain type differential conversion circuit 412 which converts an input signal Sto a differential signal S/S, and a latch circuit 414 which transitions its state in response to a differential output S/Sof the differential conversion circuit 412 as a trigger; a driver 420 for driving the high-side transistor 302 according to an output of the level shift circuit 410; a bootstrap circuit 430 for generating a bootstrap voltage Vwhich makes an upside power source of the driver; and a protection circuit 440 which works on at least part of the drive circuit 400 except for the input signal Sso that the high-side transistor 302 is turned off when an abnormality is sensed.SELECTED DRAWING: Figure 2