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US 12,763,728 B2Granted
Data driving circuit and display including the same
AssigneeLx Semicon Co., Ltd.
InventorsYong Sung Ahn, Ji Won Kim, Hyo Joong Kim, Kyung Min Shin, Kyu Tae Lee, Ha Rim Choi
Life of this patent
Estimating the term…
Abstract
The present disclosure relates to an offset elimination operation of an internal operational amplifier of a data driving circuit and relates to a technique that applies different offset elimination methods for each position of an operational amplifier.
Claims20
A gamma voltage generation circuit comprising:
- a resistor string;
- a first operational amplifier circuit connected to an uppermost end of the resistor string and configured to output a first voltage corresponding to a highest voltage of the resistor string;
- a second operational amplifier circuit connected to a lowest end of the resistor string and configured to output a second voltage corresponding to a lowest voltage of the resistor string;
- and
- a third operational amplifier circuit connected to a node of the resistor string and configured to divide the first voltage and the second voltage and to output a third voltage,
- wherein the third operational amplifier circuit includes a first offset elimination circuit configured to eliminate an offset voltage through charging and discharging of a capacitor by an Auto-Zeroing method, the Auto-Zeroing method including storing the offset voltage in the capacitor during a sampling interval and eliminating the offset voltage during a different interval based on the stored voltage, and
- the first operational amplifier circuit and the second operational amplifier circuit are configured to eliminate an offset voltage by a chopping method including periodically switching connections of input and output terminals, and
- wherein the Auto-Zeroing method is applied to the third operational amplifier circuit connected to the node of the resistor string, and the chopping method is applied to the first operational amplifier circuit and the second operational amplifier circuit connected to opposite ends of the resistor string, such that different offset elimination methods are selectively applied according to positions of the operational amplifier circuits.
5 more elements
A data driving circuit comprising:
- a data voltage generation circuit configured to supply a data voltage to a pixel through a data line;
- and
- a gamma reference voltage generation circuit configured to distribute a power supply voltage formed at both ends of a resistor string to generate a gamma reference voltage and supply the gamma reference voltage to the pixel through the data line,
- wherein the gamma reference voltage generation circuit includes:
- the resistor string;
- a first operational amplifier circuit connected to a first end of the resistor string;
- a second operational amplifier circuit connected to a second end of the resistor string;
- and
- a third operational amplifier circuit connected to a node of the resistor string,
- wherein the third operational amplifier circuit includes a first offset elimination circuit configured to eliminate an offset voltage through charging and discharging of a capacitor by an Auto-Zeroing method, the Auto-Zeroing method including storing the offset voltage in the capacitor during a sampling interval and eliminating the offset voltage during a different interval based on the stored voltage, and
- the first operational amplifier circuit and the second operational amplifier circuit include a third offset elimination circuit configured to eliminate an offset voltage by a chopping method including periodically switching connections of input and output terminals, and
- wherein the Auto-Zeroing method is applied to the third operational amplifier circuit connected to the node of the resistor string, and the chopping method is applied to the first operational amplifier circuit and the second operational amplifier circuit connected to opposite ends of the resistor string, such that different offset elimination methods are selectively applied according to positions of the operational amplifier circuits.
9 more elements
A method of eliminating an offset comprising:
- eliminating an offset voltage of a first operational amplifier circuit connected to a first end of a first resistor string and outputting a first gamma reference voltage;
- eliminating an offset voltage of a second operational amplifier circuit connected to a second end of the first resistor string and outputting a second gamma reference voltage;
- eliminating an offset voltage of a third operational amplifier circuit connected to a node of the first resistor string and outputting a third gamma reference voltage;
- and
- selecting and supplying a voltage between a maximum reference voltage and a minimum reference voltage through a second resistor string,
- wherein eliminating the offset voltage of the third operational amplifier circuit includes performing an Auto-Zeroing method including storing the offset voltage in a capacitor during a sampling interval and eliminating the offset voltage during a different interval based on the stored voltage, and
- eliminating the offset voltage of the first operational amplifier circuit and the second operational amplifier circuit includes performing a chopping method including periodically switching connections of input and output terminals, and
- wherein the Auto-Zeroing method is performed for the third operational amplifier circuit connected to the node of the first resistor string, and the chopping method is performed for the first and second operational amplifier circuits connected to opposite ends of the first resistor string, such that different offset elimination methods are selectively applied according to positions of the operational amplifier circuits.
5 more elements
Dependencies are inferred from the claim text.