Source driver capable of high speed charging and discharging
Provided are a source driver for receiving a digital signal and providing a grayscale signal corresponding to the digital signal and a display device for displaying content. The source driver includes an amplifier configured to provide a grayscale signal, a second driving switch configured to provide the grayscale signal provided by the amplifier to an output node or block the grayscale signal, and a first driving unit including a first switch whose one end is connected to a first voltage and whose other end is connected to the output node and a second switch whose one end is connected to a second voltage and whose other end is connected to the output node, and configured to first drive the output node. The output node is first driven by the first driving unit and then second driven by the amplifier with the grayscale signal.
1. A source driver for receiving a digital signal and providing a grayscale signal corresponding to the digital signal, the source driver comprising:
an amplifier configured to provide the grayscale signal;
a second driving switch configured to provide the grayscale signal provided by the amplifier to an output node or block the grayscale signal; and
a first driving unit including a pumping capacitor and configured to first drive the output node at a voltage charged in the pumping capacitor,
wherein the output node is first driven by the first driving unit and then second driven by the amplifier with the grayscale signal,
wherein the first driving unit comprises:
a pumping voltage source configured to provide a pumping voltage; and
the pumping capacitor configured to be charged with the pumping voltage,
wherein the pumping voltage provided by the pumping voltage source and the pumping voltage charged in the pumping capacitor are added and drive the output node,
wherein a time in which the first driving unit first drives the output node corresponds to an electrical distance between the source driver and a pixel connected to the output node, and
wherein the electrical distance includes a length of a source line which connects the source driver and the pixel.
2. The source driver of claim 1 , wherein the second driving switch is turned off while the output node is first driven by the first driving unit and turned on after the first driving.
3. The source driver of claim 1 , wherein a time in which the first driving unit first drives the output node corresponds to an electrical distance between the source driver and a pixel connected to the output node.
4. The source driver of claim 1 , wherein the amplifier is a unity gain buffer amplifier.
5. The source driver of claim 1 wherein a time in which the first driving unit first drives the output node corresponds to a difference between a voltage provided to the output node and a voltage of the grayscale signal to be provided to the output node.
6. A display device for displaying content, the display device comprising:
a timing controller;
a gate driver;
a display panel; and
a source driver configured to receive a digital signal and output a grayscale signal corresponding to the digital signal,
wherein the source driver comprises:
an amplifier configured to provide the grayscale signal;
a second driving switch configured to provide the grayscale signal provided by the amplifier to an output node or block the grayscale signal; and
a first driving unit configured to first drive the output node at an intended voltage,
wherein the output node is first driven by the first driving unit and then second driven by the amplifier at a grayscale voltage,
wherein the first driving unit comprises:
a pumping voltage source configured to provide a pumping voltage; and
a pumping capacitor configured to be charged with the pumping voltage,
wherein the pumping voltage provided by the pumping voltage source and the pumping voltage charged in the pumping capacitor are added and drive the output node,
wherein a time in which the first driving unit first drives the output node corresponds to an electrical distance between the source driver and a pixel connected to the output node, and
wherein the electrical distance includes a length of a source line which connects the source driver and the pixel.