Button control circuit for single-cell battery-powered system

Abstract

The invention discloses a key control circuit for a single-battery power supply system and relates to the technical field of electronic circuits. The key control circuit comprises an electric level switching circuit, a key circuit and a boosted circuit which are respectively and electrically connected with a main control chip. The electric level switching circuit comprises a triode Q6, an collector electrode of the triode Q6 is electrically connected with SW-DET of a general purpose input / output (GPIO) port of the main control chip, the collector electrode of the triode Q6 is further electrically connected with a power supply pin VDDIO of the GPIO port of the main control chip through a pull-up resistor R26, an emitter of the triode Q6 is connected with the ground, and a base electrode of the triode Q6 is electrically connected with the key circuit. The key control circuit use switch characteristics of the triode Q6, can switch logic electric level of a key S1 into input / output (IO) electric level which can be recognized by the main control chip, can provide high work voltage for the main control chip, can guarantee that the main control chip can rightly recognize a state of the key and achieves normal startup and shutdown of electronic equipment.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to a key control circuit applied to an electronic device powered by a single battery and lightly touched with a rebound key for on / off control. Background technique [0002] At present, there are many low-power electronic devices, such as stylus pens, point reading pens, and some remote controls. These electronic devices have very low power consumption and can be powered by a single 1.5V battery. Battery power supply can reduce the size of these electronic devices, and can also make battery replacement more convenient. However, the operating voltage of the main control chip in these electronic devices is higher than 1.5V, mostly 1.8V, 3.3V or 5V, etc., which requires the battery to use a booster circuit to convert the battery voltage when supplying power to the main control chip. For the working voltage of the main control chip, the boost circuit is usually composed of ...

AI Technical Summary

Problems solved by technology

[0004] When the above-mentioned single-cell battery-powered circuit is combined with a light-touch rebound button to control an electronic device, the electronic device will not work properly

Because the working voltage of the main control chip of electronic equipment is higher than the power supply voltage of a single battery, the high level identified by the main control chip is higher than the voltage of a single battery, which will cause the main control chip to fail to recognize the button action, even if The key has been pressed, but the main control chip still thinks that the input is low level and judges that the key is not pressed, so the electronic device cannot be shut down normally

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