Multi-function voltage regulator

A multi-function voltage regulator for increasing or decreasing a voltage of a power supply module and then generating an output voltage, the multi-function voltage regulator comprising:

• a first transistor, having a gate, a first terminal connected to a first node, and a second terminal connected to a second node, wherein the first node is connected to a positive terminal of the power supply module;
• a second transistor, having a gate, a first terminal connected to the first node, and a second terminal connected to a third node serving as a voltage output node;
• and
• a voltage control unit, which has a first output terminal and a second output terminal for respectively controlling the first transistor and the second transistor so that the output voltage is a default voltage, wherein the voltage control unit further has a first input terminal connected to the second node, a second input terminal connected to the voltage output node and a ground terminal connected to a ground node which is connected to a negative terminal of the power supply module, and the voltage control unit utilizes a voltage of the second node as a mode selection signal for DCDC function or LDO function;
• wherein the multi-function voltage regulator is a DCDC voltage regulator for increasing the voltage of the power supply module when the second node is connected to the negative terminal of the power supply module, and the multi-function voltage regulator is an LDO voltage regulator decreasing the voltage of the power supply module when the second node is connected to the positive terminal of the power supply module.