| 摘要 |
PROBLEM TO BE SOLVED: To provide superior supply voltage dependency of an offset voltage by eliminating deviation in voltage between collector and emitter owing to source voltage fluctuation. SOLUTION: A buffer circuit includes transistor t1, t2 with each base connected to BIAS1, a constant current circuit, by which the sum of an effusion current and an input current of an emitter of the transistor t1 is made constant current, and a first mirror circuit 3, by which collector current of the transistor t1 and collector current of the transistor t2 are made same. The first mirror circuit 3 has a transistor t3 with a collector connected to a collector of the transistor t1, and a transistor t4 with a collector connected to a collector of the transistor t2. A voltage based on a voltage Vref is fed to a connection point between the transistor t3 and the transistor t1 and to a connection point between the transistor t4 and the transistor t2. COPYRIGHT: (C)2009,JPO&INPIT
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