| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for single-end offset compensation of an operational amplifier. SOLUTION: The method for single-end compensation of an operational amplifier comprises an operational amplifier 1 designed in a single-end offset style, a common-mode circuit 2, a switch circuit 3, a comparator 4, a digital circuit 5, and a compensation circuit 6. A set of double-end input signals of the operational amplifier 1 are input the common mode circuit 2 and the switch circuit 3, and an average signal is generated by the common mode circuit 2 and is input to the operational amplifier 1 by the switching circuit 3, and an output of the operational amplifier 1 generates a single-end offset voltage difference D. The voltage difference is input to the comparator, and an initial output is generated to trigger the digital circuit 5. The digital circuit 5 generates a set of digital signals, on the basis of time to cause the compensation circuit 6 to generate a corresponding compensation current. The compensation current of the compensation circuit 6 is provided to the operational amplifier 1, to compensate the voltage difference D of the operational amplifier 1, so that the voltage difference D approaches zero. When the voltage difference D of the operational amplifier 1 is zero, the output of the comparator 4 changes the state and is detected by the digital circuit 5; and the digital circuit 5 fixes the set of digital signals and instructs the switch circuit 3 to block the average signal of the common mode circuit 2 and makes the set of double-end input signals to be input directly to the operational amplifier 1. COPYRIGHT: (C)2007,JPO&INPIT
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