| 摘要 |
PROBLEM TO BE SOLVED: To make exactly compensable the offset voltage of an operational amplifier, a comparator, etc. over a long time, without passing through other analog blocks. SOLUTION: A switched capacitor SC411 is connected to a connection point (drain) of a transistor N411 and a transistor P411 at the input of a current mirror which form a differential pair in a differential amplifier circuit. Its switching frequency is suitably changed to change the resistance value of an equivalent resistance. This slightly changes the charge drawing quantity to reduce the voltage offset of the differential amplifier circuit. COPYRIGHT: (C)2004,JPO
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