Power supply switching device and power amplifier module

A power supply switching device comprising:

• a switch circuit comprising:
• a first switching transistor having a first power supply end that is electrically connected to a first power supply that supplies a first voltage, a first amplifier end that is electrically connected to a power amplifier that amplifies and outputs a high frequency signal, and a first control end configured to control electric conduction between the first power supply end and the first amplifier end,
• a second switching transistor having a second power supply end that is electrically connected to a second power supply that supplies a second voltage different from the first voltage, a second amplifier end that is electrically connected to the power amplifier, and a second control end configured to control electric conduction between the second power supply end and the second amplifier end, and
• a shunt unit comprising at least one shunt transistor, the at least one shunt transistor having a connection end that is electrically connected between the first amplifier end and the power amplifier or between the second amplifier end and the power amplifier, a ground end that is electrically connected to ground, and a shunt control end configured to control electric conduction between the connection end and the ground end;
• and
• a control circuit configured to control a voltage or a current at each of the first control end, the second control end, and the shunt control end,
• wherein the control circuit is configured to stop supply of a control voltage or a control current to the first control end based on a control signal indicating that switching between a first connection state and a second connection state, such that a non-conducting state is established between the first power supply end and the first amplifier end,
• wherein in the first connection state, the first voltage is supplied from the first power supply through the first switching transistor to the power amplifier,
• wherein in the second connection state, the second voltage is supplied from the second power supply through the second switching transistor to the power amplifier,
• wherein when the voltage or the current at the first control end has decreased to a first threshold voltage or a first threshold current and the first power supply end and the first amplifier end are in a non-conducting state, the control circuit is configured to supply the control voltage or the control current to the shunt control end such that a conducting state is established between the connection end and the ground end,
• wherein after the conducting state is established between the connection end and the ground end, when the voltage or the current at the shunt control end has increased to a setting voltage or a setting current, the control circuit is configured to stop supply of the control voltage or the control current to the shunt control end such that the non-conducting state is established between the connection end and the ground end, and
• wherein when the voltage or the current at the shunt control end has decreased to a second threshold voltage or a second threshold current, the control circuit is configured to supply the control voltage or the control current to the second control end such that the second connection state is entered.