Aerosol generating device
According to an embodiment, an aerosol generating device may include a battery configured to supply a battery voltage, a first boost circuit configured to boost the battery voltage to a first boost voltage higher than the battery voltage, a second boost circuit configured to generate first and second switching voltages respectively based on first and second PWM signals, and boost the first boost voltage to a second boost voltage according to the generated first and second switching voltages, a vibrator configured to generate ultrasonic vibration according to the second boost voltage, and atomize an aerosol generating material, and a processor configured to control the battery, the first boost circuit, and the second boost circuit.
1 . An aerosol generating device comprising:
a battery configured to supply a battery voltage;
a first boost circuit configured to boost the battery voltage to a first boost voltage higher than the battery voltage;
a second boost circuit configured to generate first and second switching voltages respectively based on first and second PWM signals, and boost the first boost voltage to a second boost voltage according to the generated first and second switching voltages;
a vibrator configured to generate ultrasonic vibration according to the second boost voltage, and atomize an aerosol generating material; and
a processor configured to control the battery, the first boost circuit, and the second boost circuit.
2 . The aerosol generating device of claim 1 , wherein the second boost circuit includes:
a power drive circuit configured to generate the first and second switching voltages respectively based on the first and second PWM signals input from the processor; and
a voltage boost circuit configured to boost the first boost voltage to the second boost voltage according to the first and second switching voltages output from the power drive circuit.
3 . The aerosol generating device of claim 2 , wherein the boost circuit includes:
a first inductor having one terminal to which the first boost voltage is applied and another terminal connected to one terminal of the vibrator;
a first transistor connected to another terminal of the first inductor and configured to switch a current flowing between the first inductor and a ground according to the first switching voltage;
a second inductor having one terminal to which the first boost voltage is applied and another terminal connected to another terminal of the vibrator; and
a second transistor connected to the other terminal of the second inductor and configured to switch a current flowing between the second inductor and the ground according to the second switching voltage.
4 . The aerosol generating device of claim 2 , wherein the power drive circuit further includes an output blocking circuit configured to block an output from the power drive circuit when any one of the first and second switching voltages is less than or equal to a threshold voltage.
5 . The aerosol generating device of claim 2 , wherein the power drive circuit is implemented as one integrated circuit.
6 . The aerosol generating device of claim 1 , wherein
the first boost voltage is at least three times greater than the battery voltage, and
the second boost voltage is at least four times greater than the first boost voltage.
7 . The aerosol generating device of claim 1 , wherein the battery voltage and the first boost voltage are direct current (DC) voltages, and the second boost voltage is an alternating current (AC) voltage.
8 . The aerosol generating device of claim 1 , wherein the first boost circuit includes:
a DC-DC converter including an input terminal to which the battery voltage is applied, a switch terminal connected to the input terminal through a power inductor, a reference voltage terminal, and an output terminal for outputting the first boost voltage;
a first resistor having one terminal connected to the output terminal and another terminal connected to the reference voltage terminal; and
a second resistor having one terminal connected to the reference voltage terminal and another terminal connected to a ground.
9 . The aerosol generating device of claim 8 , wherein the DC-DC converter is configured to output the first boost voltage based on a ratio of the first resistor to the second resistor.
10 . The aerosol generating device of claim 3 , wherein
the first transistor includes a semiconductor switch configured to switch a current flowing between a source electrode of the first transistor connected to ground and a drain electrode of the first transistor connected to the other terminal of the first inductor, according to the first switching voltage applied to a gate electrode of the first transistor, and
the second transistor includes another semiconductor switch configured to switch a current flowing between a source electrode of the second transistor connected to the ground and a drain electrode of the second transistor connected to the other terminal of the second inductor, according to the second switching voltage applied to a gate electrode of the second transistor.
11 . The aerosol generating device of claim 1 , wherein the first PWM signal and the second PWM signal are complementary to each other.
12 . The aerosol generating device of claim 3 , wherein, when the first switching voltage is at a first level and the second switching voltage is at a second level,
a current flows between one of the first and second inductors and the ground such that energy corresponding to a change in a current flowing through the one of the first and second inductors is stored in the one of the first and second inductors, and
a current does not flow between the other of the first and second inductors and the ground such that energy stored in the other of the first and second inductors is transmitted to the vibrator.