Output Buffer with Offset Cancellation Structure and Offset Cancellation Method Using the Same

摘要

An output buffer with an offset cancellation structure for an LCD source driver includes an operational amplifier, for driving an output signal of the output buffer according to a data signal from a data input terminal of the output buffer; a reference voltage generator, for generating a reference voltage and inputting the reference voltage to the operational amplifier; and a sampling capacitor, coupled between a second input terminal of the operational amplifier and the data input terminal of the output buffer in a first phase, and coupled between the second input terminal of the operational amplifier and an output terminal of the operational amplifier in a second phase, wherein the second input terminal of the operational amplifier is further coupled to the output terminal of the operational amplifier in the first phase. The output signal outputs the data signal where the offset voltage is cancelled in the second phase.

主权项

1. An output buffer with an offset cancellation structure, for a liquid crystal display (LCD) source driver, comprising:
an operational amplifier, for driving an output signal of the output buffer according to a data signal from a data input terminal of the output buffer; a reference voltage generator, coupled to a first input terminal of the operational amplifier, for generating a reference voltage and inputting the reference voltage to the operational amplifier; and a sampling capacitor, coupled between a second input terminal of the operational amplifier and the data input terminal of the output buffer in a first phase, and coupled between the second input terminal of the operational amplifier and an output terminal of the operational amplifier in a second phase, wherein the second input terminal of the operational amplifier is further coupled to the output terminal of the operational amplifier in the first phase; wherein the output signal outputs the reference voltage with an offset voltage in the first phase and outputs the data signal where the offset voltage is cancelled in the second phase.