| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption when integrating a circuit by using a level shift circuit being operated by a pulse signal, and by keeping on an upper-arm switching element by the retention function of drive charge, only during a pulse period. SOLUTION: A lower arm QB1 is turned on and off by a control signal SB, via a driving circuit 3 where VCC is used as a power supply. An upper arm QT1 is driven by a drive element M5, where a power supply VCH for the upper arm is used as the power supply. An upper arm ST gives an external signal from a circuit 11 for driving switching elements S1 and S2 by a signal with the same logic as an upper-arm switching element to have it operate. When the element S1 is turned on and voltage drops in a resistor Ra for lowering potential, the signal is transferred by logic inverters 8 and 9, and a P- channel switching element M5 is turned on for driving the QT1. After the drive period of QT1, the P-channel switching element M5 is turned off, and if the QT1 that is a voltage-type switching element is once driven, a driving voltage is kept and on-state is maintained, since the QT1 is a voltage-type switching element. |
