| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a load drive device that can reduce variations in constant current for driving a load. <P>SOLUTION: One end of a shunt resistor 20 is connected to an inverting input terminal of an operational amplifier 34, and the other end of the shunt resistor 20 is connected to a non-inverting input terminal of the operational amplifier 34 via a reference power supply 32. A current flowing through the shunt resistor 20 flows to a gate of an IGBT as a load 10 via a first switching element 35 in a drive circuit 30. Specifically, the operational amplifier 34 exercises feedback-control of a gate of the first switching element 35 so as to satisfy Vref=Rout×Ic, where Vref is the value of a reference voltage of the reference power supply 32, Rout is the resistance value of the shunt resistor 20, and Ic is the value of a constant current flowing to the load 10. This controls the magnitude of the current flowing through the shunt resistor 20 at a constant level to reduce variations in the constant current flowing to the load 10. <P>COPYRIGHT: (C)2012,JPO&INPIT |
