High-side transistor drive circuit, DC / DC converter control circuit using it, DC / DC converter

摘要

PROBLEM TO BE SOLVED: To provide a drive circuit capable of preventing a malfunction of a high-side transistor. A UVLO circuit 440, the difference ΔV of the voltage _{V S} of the bootstrap voltage _{V B} and the switching line, is lower than the threshold value _{V UVLO,} asserts an anomaly detection (UVLO) signal. The latch circuit 414A includes a first transistor M21 to a fifth transistor M25. The fifth transistor M25 is connected in parallel with the first transistor M21 and is turned on when the UVLO signal is asserted. [Selection diagram] Fig. 4