| 摘要 |
PURPOSE:To suppress fluctuation of output current by providing two H-bridge output circuits having current detecting circuits, feeding voltage at the current detecting terminal through a resistor to the input of an operational amplifier and comparing with a reference voltage and then controlling the gate voltage of a MOS transistor in the output H-bridge circuit. CONSTITUTION:Drains of N channel MOS transistors 24, 26 and 25, 27 are connected, respectively, to a power supply terminal 3 and a current detecting terminal 35 while sources thereof are connected, respectively, to the current detecting terminal 35 and output terminals 19, 20. Gates of the transistors 24, 25 and 26, 27 are connected to internal input terminals 7, 8. Output is constituted of two H-bridge circuits in such a manner, and the voltages at the current detecting terminals 35, 36 are provided through resistors 32, 33 to the input of an operational amplifier 34 where they are compared with the output from a reference voltage generating circuit 6 in order to control the gate voltage of the MOS transistors 24-27. By such arrangement, fluctuation of output current can be suppressed. |
