| 摘要 |
PROBLEM TO BE SOLVED: To provide a class A output circuit provided with an idling current control function wherein an output voltage level is decreased up to around a GND level and an idling current is reduced small. SOLUTION: The class A output circuit includes a current mirror circuit CM 11 wherein an output transistor Q1 and a constant current source CG are connected in a mirror ratio of N:1. The output circuit outputs a load current from a connecting point between the transistor Q1 and the current mirror circuit CM 11. An idling current control circuit IDC includes current mirror circuits CM12 and CM13, the current mirror circuit CM 12 is connected to the transistor Q1 and the current mirror circuit CM 13 in a mirror ratio of 1:1, and the second current mirror circuit CM 13 is connected to a connecting point between the constant current source CG and the current mirror circuit CM 11 and the first current mirror circuit CM 12 in a mirror ratio of 1:1, and the idling current is controlled depending on a load current. COPYRIGHT: (C)2004,JPO
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