Output current pumping circuit and remote controller using the same

Abstract

The present invention relates to a remote control IC having a circuit for pumping up current of an output port and a remote controller implemented to be capable of operating with one battery of about 1.5V using the IC. In the remote controller, an infrared LED emits light through the remote control IC, so that signals are transmitted to devices to be controlled such as a television set.; In order to perform all functions normally even at low voltage and particularly to secure a sufficient transmission distance by driving the infrared LED, the present invention implements a remote controller comprising a remote control IC having a circuit for pumping up output current of an output port, which needs high output current, even at low voltage, and a battery of about 1.5V for driving the remote controller, wherein the infrared LED is driven by the pumped up output current of the output port of the remote control IC, whereby the remote controller can maintain a sufficient transmission distance with only one battery of about 1.5V.; The output port according to the present invention has an output current pumping circuit for detecting a level of power voltage according to the drop of the power voltage, boosting the power voltage, and supplying a voltage boosted higher than the power voltage to the gate of a MOS transistor to obtain output current of high voltage. The output current pumping circuit comprises a power voltage detection unit for determining a level of the power voltage, a boost circuit unit for boosting the power voltage depending on an effective signal of the power voltage detection unit, and a data conversion unit for receiving the changed (boosted) power voltage and controlling the changed (boosted) power voltage in response to a transmission signal to supply gate voltage of the MOS transistor for outputting final current.

Description

technical field [0001] The present invention relates to a circuit for pumping current from an output port and a remote controller having the circuit, and in particular, to an output current pumping circuit, wherein the output port of the present invention detects a voltage related to a power supply drop the level of the supply voltage, and boost and supply this voltage to obtain high voltage output current. Background technique [0002] Generally, if one or more keys are input through the keypad of the matrix structure in the remote controller, the output port of the key matrix is ​​sequentially turned into a low state one by one by the port control unit, and the The key input port of the structure of the pull-up resistor to read each key input. If a low input is read, a transmission signal of a predetermined format is generated at the associated output and input ports, and the driver is embedded in the figure 1 The output n-channel MOSFET (NMOS) transistor 100 in the show...

AI Technical Summary

Problems solved by technology

Therefore, there is a problem that since the resistance of the existing pull-up resistor is close to the resistance of the off resistor of the key in the key matrix, the input port An is read as low state, so that the IC will mistakenly think that the button is turned on

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