An electronic circuit is included, which acts as a zener diode below a zener voltage, and as a constant current source above the zener voltage comprising an input terminal, an output terminal, a first resistor, a second resistor, a third resistor, a fourth resistor, a first NPN-transistor, a second NPN-transistor, a PNP-transistor, and a voltage reference, where the zener voltage of the electronic circuit can be selected by a user.

A power semiconductor circuit is provided for clamping the voltage across the circuit when a power semiconductor switch is opened (i.e., turned off). The circuit may include a first surge arrester and a first semiconductor switch coupled in parallel with the power semiconductor switch. The first semiconductor switch is coupled in series with the first surge arrester. A second surge arrester may be coupled to the gate of the first semiconductor switch to control current flow through the first semiconductor switch and the first surge arrester.

A power semiconductor circuit is provided for clamping the voltage across the circuit when a power semiconductor switch is opened (i.e., turned off). The circuit may include a first surge arrester and a first semiconductor switch coupled in parallel with the power semiconductor switch. The first semiconductor switch is coupled in series with the first surge arrester. A second surge arrester may be coupled to the gate of the first semiconductor switch to control current flow through the first semiconductor switch and the first surge arrester.

A power supply unit includes: a power supply configured to discharge power to a load for generating an aerosol from an aerosol generation source; a charger configured to convert inputted power into charging power; a temperature measuring unit configured to measure a temperature of the power supply; and a charging controller configured to perform a first control for stopping the charger from supplying the charging power to the power supply and a second control for causing the charger to supply the charging power to the power supply, the charging controller setting a duty ratio to a value greater than 0 and smaller than 100 in a case where the temperature of the power supply is within a predetermined range, and the duty ratio being obtained by dividing a time during which the charging controller performs the first control by a unit time.

A power supply unit includes: a power supply configured to discharge power to a load for generating an aerosol from an aerosol generation source; a charger configured to convert inputted power into charging power; a temperature measuring unit configured to measure a temperature of the power supply; and a charging controller configured to perform a first control for stopping the charger from supplying the charging power to the power supply and a second control for causing the charger to supply the charging power to the power supply, the charging controller setting a duty ratio to a value greater than 0 and smaller than 100 in a case where the temperature of the power supply is within a predetermined range, and the duty ratio being obtained by dividing a time during which the charging controller performs the first control by a unit time.

A spike suppression circuit includes a wide bandgap transistor, a first transistor, a clamping circuit, and a capacitor. The wide bandgap transistor is depletion-type. The first transistor is coupled in series with the wide bandgap transistor. The clamping circuit provides a voltage difference, and is coupled to a common node between the wide bandgap transistor and the first transistor. The capacitor provides a supply voltage for the clamping circuit. When the first transistor is turned off, the capacitor can recycle spike energy at the common node.

A spike suppression circuit includes a wide bandgap transistor, a first transistor, a clamping circuit, and a capacitor. The wide bandgap transistor is depletion-type. The first transistor is coupled in series with the wide bandgap transistor. The clamping circuit provides a voltage difference, and is coupled to a common node between the wide bandgap transistor and the first transistor. The capacitor provides a supply voltage for the clamping circuit. When the first transistor is turned off, the capacitor can recycle spike energy at the common node.

A TVS circuit having a first diode with a cathode coupled to a first terminal and an anode coupled to a first node. A second diode has an anode coupled to a second node and a cathode coupled to a third node. A third diode is coupled between the first node and second node. A fourth diode is coupled between the first node and third node. A fifth diode is coupled between the second node and a second terminal. A sixth diode is coupled between the second terminal and the third node. A seventh diode can be coupled between the second terminal and an intermediate node between the fifth diode and sixth diode. The first diode is disposed on a first semiconductor die, while the second diode is disposed on a second semiconductor die. Alternatively, the first diode and second diode are disposed on a single semiconductor die.

A TVS circuit having a first diode with a cathode coupled to a first terminal and an anode coupled to a first node. A second diode has an anode coupled to a second node and a cathode coupled to a third node. A third diode is coupled between the first node and second node. A fourth diode is coupled between the first node and third node. A fifth diode is coupled between the second node and a second terminal. A sixth diode is coupled between the second terminal and the third node. A seventh diode can be coupled between the second terminal and an intermediate node between the fifth diode and sixth diode. The first diode is disposed on a first semiconductor die, while the second diode is disposed on a second semiconductor die. Alternatively, the first diode and second diode are disposed on a single semiconductor die.

A circuit includes a current source series-connected with a load between first and second terminals and an element coupled in parallel with the load between the first and second terminals. A value of a current in the current source is controlled based on a current flowing in the element between the first and second terminals. The value of the current in the current source is controlled proportional to power consumption in the load based on the current flowing in the element between the first and second terminals. The element is used to limit a voltage across the load while the value of the current is being controlled.