Current regulator and method for efficiency improvement of a LED display system
AssigneeRichtek Technology Corporation
InventorsShui-Mu Lin, Tsung-Wei Huang, Jien-Sheng Chen
Life of this patent
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Abstract
For efficiency improvement of a LED display system including a charge pump and a LED connected to either the voltage input terminal or the voltage output terminal of the charge pump, either one or both of two current regulators are enabled according to a voltage detected from the LED, for establishing a driving current for the LED. When the detected voltage is higher than a threshold, the first one of the current sources is enabled sole. When the detected voltage is lower than the threshold, the second one of the current sources is enabled sole, or both the current sources are enabled, or the current sources are alternatively enabled.
Claims22
A current regulator for efficiency improvement of a LED display system including a charge pump and a LED connected between a voltage input terminal of the charge pump and a node, the current regulator comprising:
- a first current source connected between the node and a ground terminal;
- a second current source connected between the node and a voltage output terminal of the charge pump;
- and
- a mode decision circuit connected to the first and second current sources to enable at least one of the first and second current sources for establishing a driving current for the LED.
A current regulator for efficiency improvement of a LED display system including a charge pump and a LED connected between a ground terminal and a node, the current regulator comprising:
- a first current source connected between the node and a voltage input terminal of the charge pump;
- a second current source connected between the node and a voltage output terminal of the charge pump;
- and
- a mode decision circuit connected to the first and second current sources to enable at least one of the first and second current sources for establishing a driving current for the LED.
A method for efficiency improvement of a LED display system including a charge pump and a LED connected between a voltage input terminal of the charge pump and a node, the method comprising the steps of:
- detecting a voltage at the node;
- and
- according to the voltage at the node, enabling at least one of a first current source connected between the node and a ground terminal and a second current source connected between the node and a voltage output terminal of the charge pump, for establishing a driving current for the LED.
A method for efficiency improvement of a LED display system including a charge pump and a LED connected between a node and a ground terminal, the method comprising the steps of:
- detecting a voltage at the node;
- and
- according to the voltage at the node, enabling at least one of a first current source connected between a voltage input terminal of the charge pump and the node and a second current source connected between a voltage output terminal of the charge pump, for establishing a driving current for the LED.
Dependencies are inferred from the claim text.