| 摘要 |
PROBLEM TO BE SOLVED: To provide a self-bias circuit which can shorten a start-up time from a power down state to a generation of constant current. SOLUTION: A self-bias circuit used as a constant current source is provided with a transfer gate which is a switch for power down composed of a first NMOS transistor and a first PMOS transistor, a constant current generation circuit with a current mirror circuit composed of a second PMOS transistor and a third PMOS transistor, a start-up circuit starting up the constant current generation circuit, a power down circuit switching over an operation state of the constant current generation circuit by providing a power down signal to a transfer gate, a transfer gate control circuit interrupting the first NMOS transistor by providing an L level to a gate of the first NMOS transistor, and a switchover circuit switching over an input of the transfer gate control circuit. COPYRIGHT: (C)2006,JPO&NCIPI
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