| 摘要 |
PROBLEM TO BE SOLVED: To start a constant-voltage output from a voltage generation circuit without overshooting the constant-voltage by suppressing an inrush current at start-up. SOLUTION: The constant-voltage circuit device includes an output transistor M1 to output an electrical current from an input terminal IN to the output terminal Vout in accordance with an input control signal, a reference voltage circuit 1 to generate a reference voltage, a control circuit 2 to control the operation of the output transistor M1 so as to adjust a proportional voltage proportional to the output voltage output from the output terminal IN to be a predetermined reference voltage generated from the reference voltage circuit 1, and a soft start circuit 4 including a capacitor C1 for soft start that is charged at start-up and a control transistor M6 to control a current supplied to the reference voltage circuit 1. The control transistor M6 adjusts the reference voltage circuit 1 to a voltage determined by the capacitor C1 for soft start at the start-up until the reference voltage circuit 1 reaches a desired voltage. COPYRIGHT: (C)2010,JPO&INPIT |
