Voltage generation circuit

A voltage generation circuit, comprising:

• a buck circuit and a charge pump circuit;
• wherein the buck circuit includes a second switching transistor, a second diode for freewheeling and a second inductor for storing energy, wherein a first end of the second switching transistor is connected to an input terminal of an input voltage, a second end of the second switching transistor is connected to a cathode of the second diode, a control end of the second switching transistor is connected with a control signal;
• an anode of the second diode is connected to a ground;
• a first end of the second inductor is connected to the cathode of the second diode, a second end of the second inductor is connected to a digital voltage output terminal;
• the cathode of the second diode is connected to a voltage input terminal of the charge pump circuit, the voltage on the cathode of the second diode is outputted as an auxiliary voltage for generating a reference voltage after being boosted by the charge pump circuit;
• and
• wherein the charge pump circuit is connected to an external voltage source that is different from the input voltage supplied to the buck circuit.