A first terminal receives a first DC voltage. A switch selectively couples the first terminal to a second terminal providing an output. A control circuit selectively actuates the switch in response to a comparison of the first DC voltage to a second DC voltage. A low-dropout (LDO) linear voltage regulator, connected between the first and third terminals, operates to provide the second DC voltage from the first DC voltage.

A power supply unit for an aerosol inhaler includes: a power supply able to discharge power to a load for generating an aerosol from an aerosol source; a connector able to be electrically connected to an external power supply; a control device configured to control at least one of charging and discharging of the power supply or configured to be able to convert power which is input from the connector into charging power for the power supply; and a zener diode provided between the connector and the control device so as to be connected in parallel with the control device. A maximum value of zener voltage of the zener diode is lower than a maximum operation guarantee voltage of the control device.

A power supply unit for an aerosol inhaler includes: a power supply able to discharge power to a load for generating an aerosol from an aerosol source; a connector able to be electrically connected to an external power supply; a control device configured to control at least one of charging and discharging of the power supply or configured to be able to convert power which is input from the connector into charging power for the power supply; and a zener diode provided between the connector and the control device so as to be connected in parallel with the control device. A maximum value of zener voltage of the zener diode is lower than a maximum operation guarantee voltage of the control device.

An auxiliary power supply circuit operating within a wide input voltage range has a voltage follower unit and a voltage comparison unit. The voltage follower unit has an electronic switch, a resistor, and a Zener diode. The electronic switch has a first terminal electrically connected to a voltage input terminal of the working voltage conversion circuit, a second terminal electrically connected to a voltage output terminal of the working voltage conversion circuit, and a control terminal. The resistor is electrically connected between the first terminal and the control terminal of the electronic switch. The Zener diode has a cathode electrically connected to the control terminal of the electronic switch. The voltage comparison unit has a detecting terminal electrically connected to the voltage input terminal of the working voltage conversion circuit, and an output terminal electrically connected to the control terminal of the electronic switch.

An auxiliary power supply circuit operating within a wide input voltage range has a voltage follower unit and a voltage comparison unit. The voltage follower unit has an electronic switch, a resistor, and a Zener diode. The electronic switch has a first terminal electrically connected to a voltage input terminal of the working voltage conversion circuit, a second terminal electrically connected to a voltage output terminal of the working voltage conversion circuit, and a control terminal. The resistor is electrically connected between the first terminal and the control terminal of the electronic switch. The Zener diode has a cathode electrically connected to the control terminal of the electronic switch. The voltage comparison unit has a detecting terminal electrically connected to the voltage input terminal of the working voltage conversion circuit, and an output terminal electrically connected to the control terminal of the electronic switch.

A power supply circuit configured to generate an output voltage at a target level from an input voltage thereof. The power supply circuit includes a wiring configured to receive the input voltage, a variable resistor provided between the wiring and a predetermined node, a voltage generation circuit configured to apply a voltage at a predetermined level to the predetermined node based on a current from the variable resistor, an output circuit configured to output the output voltage at the target level, in response to the voltage at the predetermined level being applied to the predetermined node, and an adjustment circuit configured to increase a resistance value of the variable resistor in response to a predetermined time period having elapsed since starting of generation of the output voltage.

The switching circuit includes a first capacitor to which a pulse signal output from a control unit is input, a rectification circuit including at least a first diode and a second diode, the rectification circuit rectifying a voltage input from the first capacitor, and generating a first voltage, and a first switching element including a first terminal, a second terminal and a third terminal, the first voltage generated by the rectification circuit being applied between the first terminal and the second terminal.

The switching circuit includes a first capacitor to which a pulse signal output from a control unit is input, a rectification circuit including at least a first diode and a second diode, the rectification circuit rectifying a voltage input from the first capacitor, and generating a first voltage, and a first switching element including a first terminal, a second terminal and a third terminal, the first voltage generated by the rectification circuit being applied between the first terminal and the second terminal.

One example described herein includes a power switch control system. The system includes a first monitoring terminal coupled to a first terminal of a power transistor and a second monitoring terminal coupled to a second terminal of the power transistor. The power transistor and the power switch control system can form an ideal diode between the first monitoring terminal arranged as an anode and the second monitoring terminal arranged as a cathode. The system further includes a reverse current controller coupled to the first monitoring terminal and the second monitoring terminal and is configured to control activation of the power transistor to conduct a reverse current from the second monitoring terminal to the first monitoring terminal in response to a reverse voltage arranged as a cathode voltage at the second monitoring terminal being greater than an anode voltage at the first monitoring terminal.

One example described herein includes a power switch control system. The system includes a first monitoring terminal coupled to a first terminal of a power transistor and a second monitoring terminal coupled to a second terminal of the power transistor. The power transistor and the power switch control system can form an ideal diode between the first monitoring terminal arranged as an anode and the second monitoring terminal arranged as a cathode. The system further includes a reverse current controller coupled to the first monitoring terminal and the second monitoring terminal and is configured to control activation of the power transistor to conduct a reverse current from the second monitoring terminal to the first monitoring terminal in response to a reverse voltage arranged as a cathode voltage at the second monitoring terminal being greater than an anode voltage at the first monitoring terminal.