The invention provides a self-adaptive external input
voltage adjustable GPIO (
General Purpose Input / Output) circuit, which comprises a
signal transmission module, the input end of the
signal transmission module is used for inputting an external input
signal, the output end of the signal transmission module is used for being electrically connected with an internal
chip, and the signal transmission module comprises a first switching device; the external input signal is a signal input into the input and output circuit by an
external circuit; the input end of the
voltage control module is used for inputting an external input signal, the output end of the
voltage control module is electrically connected with the control end of the first switching device, and the
voltage control module is used for driving the first switching device to be switched on under the condition that the voltage of the external input signal is greater than a preset voltage; the voltage of the signal input to the internal
chip by the signal transmission module is smaller than or equal to the preset voltage. The circuit can realize self-bias voltage protection when a
chip is not powered on, can prevent
overvoltage when the chip works normally, can broaden the regulation range of IO
threshold voltage, and can meet the actual application requirements.