| 摘要 |
PROBLEM TO BE SOLVED: To provide a bias circuit that combines a high power supply voltage fluctuation rejection ratio and high-speed startability.SOLUTION: A bias circuit includes: a reference current generating unit having a first and a second reference current elements disposed in a first and a second current paths between a power terminal and a reference potential terminal; a first current mirror circuit for outputting a predetermined bias voltage from a first node connected to a control terminal of a first and a second transistors serially connected to the first and second reference current elements in the first and second current paths; a third transistor that is serially connected to a third reference current element in a third current path to configure a second current mirror circuit with the first or second transistor; a bypass capacitor connected between a second node connected to the control terminal of the third transistor and the power terminal; a start circuit for controlling the electrical potential of the first node to drive the first transistor; and a first switch that is connected between the first and second nodes and turns on when the electrical potential of the first node rises. |
