US 11,054,849 B2
Source driver and output buffer thereof
Chia-Chu Chien, Tainan (TW)
Assigned to HIMAX TECHNOLOGIES LIMITED, Tainan (TW)
Filed by HIMAX TECHNOLOGIES LIMITED, Tainan (TW)
Filed on Jul. 12, 2019, as Appl. No. 16/509,514.
Prior Publication US 2021/0011505 A1, Jan. 14, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. G09G 3/36 (2006.01); G05F 1/575 (2006.01)
CPC G05F 1/575 (2013.01) [G09G 2310/027 (2013.01); G09G 2310/0291 (2013.01); G09G 2330/021 (2013.01)] 34 Claims
OG exemplary drawing
 
1. A source driver, comprising an output buffer and a feedback circuit, wherein the output buffer comprises:
an input stage circuit, having a first input terminal and a second input terminal, wherein the first input terminal of the input stage circuit receives an input voltage of the output buffer, the second input terminal of the input stage circuit is coupled to an output terminal of the feedback circuit to receive a first feedback voltage, and the input stage circuit is configured to correspondingly generate a first gate control voltage and a second gate control voltage according to the input voltage and the first feedback voltage;
an output stage circuit, coupled to the input stage circuit to receive the first gate control voltage and the second gate control voltage, and configured to correspondingly generate an output voltage of the output buffer to a data line of a display panel according to the first gate control voltage and the second gate control voltage, wherein an output terminal of the output stage circuit is coupled to an input terminal of the feedback circuit;
a rising control circuit, configured to compare the input voltage with the first feedback voltage to obtain a first comparison result, wherein when the first comparison result indicates that the first feedback voltage is to be pulled up, the rising control circuit pulls down the first gate control voltage and the second gate control voltage during a first transient period; and
a falling control circuit, configured to compare the input voltage with the first feedback voltage to obtain a second comparison result, wherein when the second comparison result indicates that the first feedback voltage is to be pulled down, the falling control circuit pulls up the first gate control voltage and the second gate control voltage during a second transient period,
wherein the feedback circuit is configured to generate and output the first feedback voltage related to the output voltage to the second input terminal of the input stage circuit.