Patent ID: 7304465

Claim:
In a power supply circuit for generating a supply voltage based on an input constant voltage and supplying the supply voltage to a load, the improvements comprising: a delay circuit configured to delay the input constant voltage; an output circuit configured to generate the supply voltage from the input constant voltage delayed by the delay circuit and to supply the generated supply voltage to the load; and a current generation circuit generating a current based on the supply voltage that is generated by said output circuit and supplying the generated current to said output circuit as a drive current, wherein said current generation circuit includes: a first transistor whose collector and emitter are connected in serial to a current path to the output circuit, a second transistor whose collector and emitter are located between a base of the first transistor and the input constant voltage; and a third transistor whose collector is connected to a connection point between the output circuit and the delay circuit, said third transistor forming a current mirror together with the second transistor, whereby said drive current is supplied to the connection point between the output circuit and the delay circuit from the collector of the third transistor.