ELECTRONIC SYSTEM, VOLTAGE CONVERSION CIRCUIT AND METHOD THEREOF
First Claim
1. A voltage conversion circuit, used for boosting an input voltage, the voltage conversion circuit comprising:
- an energy-storing inductor, having one terminal connected to the input voltage;
a N type transistor, having drain connected to another terminal of the energy-storing inductor, having gate receiving a first driving signal and accordingly determining switched-on or switched-off state, having source connected to a ground voltage;
a P type transistor, having source connected to another terminal of the energy-storing inductor, having gate receiving a second driving signal and accordingly determining switched-on or switched-off state, having drain outputting an output voltage;
a current comparator, connected to source of the N type transistor for receiving a sensing current, wherein the current comparator compares the sensing current and a threshold current so as to determine load type and accordingly outputs a comparison signal;
a multiplexer, electrically connected to the current comparator for receiving the comparison signal, wherein the multiplexer receives the input voltage and outputting voltage and accordingly output a work voltage according to the comparison signal;
a first driver, electrically connected to the multiplexer and the N type transistor, the first driver receiving a pulse width control signal and the work voltage and accordingly output the first driving signal, wherein the first driving signal is an oscillating signal and high level voltage value of the first driving signal is equal to voltage value of the work voltage; and
a second driver, electrically connected to the current comparator and the P type transistor, the second driver receiving the comparison signal, the pulse width control signal and a predetermined DC voltage and accordingly outputting the second driving signal,wherein when current value of the sensing current is smaller than current value of the threshold current, the current comparator outputs the comparison signal with high voltage level, such that the work voltage is equal to the input voltage and voltage level of the second driving signal is the predetermined DC voltage so as to switch off the P type transistor, wherein a switching current flowing through a parasitic capacitor of the N type transistor is generated from the input voltage.
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Accused Products
Abstract
A voltage conversion circuit is disclosed. The voltage conversion circuit comprises an energy-storing inductor, an N-type transistor, a P-type transistor, a current comparator, a multiplexer, a first driver and a second driver. When load connected to the voltage conversion circuit is a light load, the P-type transistor will be switched off so as to avoid generating a switching current and the switching current flowing gate-source and gate-drain parasitic capacitor of the N-type transistor is generated from an input voltage. The number of N-type transistor and switching frequency also decrease accordingly so that voltage conversion efficiency of the voltage conversion circuit may be increased.
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Citations
19 Claims
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1. A voltage conversion circuit, used for boosting an input voltage, the voltage conversion circuit comprising:
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an energy-storing inductor, having one terminal connected to the input voltage; a N type transistor, having drain connected to another terminal of the energy-storing inductor, having gate receiving a first driving signal and accordingly determining switched-on or switched-off state, having source connected to a ground voltage; a P type transistor, having source connected to another terminal of the energy-storing inductor, having gate receiving a second driving signal and accordingly determining switched-on or switched-off state, having drain outputting an output voltage; a current comparator, connected to source of the N type transistor for receiving a sensing current, wherein the current comparator compares the sensing current and a threshold current so as to determine load type and accordingly outputs a comparison signal; a multiplexer, electrically connected to the current comparator for receiving the comparison signal, wherein the multiplexer receives the input voltage and outputting voltage and accordingly output a work voltage according to the comparison signal; a first driver, electrically connected to the multiplexer and the N type transistor, the first driver receiving a pulse width control signal and the work voltage and accordingly output the first driving signal, wherein the first driving signal is an oscillating signal and high level voltage value of the first driving signal is equal to voltage value of the work voltage; and a second driver, electrically connected to the current comparator and the P type transistor, the second driver receiving the comparison signal, the pulse width control signal and a predetermined DC voltage and accordingly outputting the second driving signal, wherein when current value of the sensing current is smaller than current value of the threshold current, the current comparator outputs the comparison signal with high voltage level, such that the work voltage is equal to the input voltage and voltage level of the second driving signal is the predetermined DC voltage so as to switch off the P type transistor, wherein a switching current flowing through a parasitic capacitor of the N type transistor is generated from the input voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A voltage conversion method, used in a voltage conversion circuit, the voltage conversion circuit comprising an energy-storing inductor, a N type transistor, a P type transistor, a current comparator, a multiplexer, a first driver and a second driver, one terminal of the energy-storing inductor connected to an input voltage, the N type transistor having drain connected to another terminal of the energy-storing inductor, having gate receiving a first driving signal and accordingly determining switched-on or switched-off state and having source connected to a ground voltage, the P type transistor having source connected to another terminal of the energy-storing inductor, having gate receiving a second driving signal and accordingly determining switched-on or switched-off state and having drain outputting an output voltage, the current comparator connected to source of the N type transistor so as to receive a sensing current and the current comparator comparing the sensing current with a threshold current so as to determine load type and to accordingly output a comparison signal, the multiplexer electrically connected to the current comparator so as to receive the comparison signal and the multiplexer receiving the input voltage and the output voltage and outputting a work voltage according to the comparison signal, the first driver electrically connected to the multiplexer and the N type transistor, the first driver receiving a pulse width control signal and the work voltage and accordingly outputting the first driving signal, the second driver electrically connected to the current comparator and the P type transistor, the second driver receiving the comparison signal, the pulse width control signal and a predetermined DC voltage and accordingly outputting the second driving signal, the voltage conversion method comprising:
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determining whether the sensing current is smaller than the threshold current via the current comparator; outputting the comparison signal with high voltage level via the current comparator when the current value of the sensing current is smaller than the current value of the threshold current; choosing the input voltage as a work voltage according to the comparison signal with high voltage level via the multiplexer; outputting the first driving signal via the first driver, wherein the first driving signal is an oscillation signal and voltage level thereof is equal to voltage level of the work voltage; and making voltage level of the second driving signal equal to the predetermined DC voltage via the second driver and thereby switching off the P type transistor; wherein the switching current flowing through a parasitic capacitor of the N type transistor is generated from the input voltage. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. An electronic system, comprising:
a voltage conversion circuit, used for boosting an input voltage, the voltage conversion circuit comprising; an energy-storing inductor, having one terminal connected to the input voltage; a N type transistor, having drain connected to another terminal of the energy-storing inductor, having gate receiving a first driving signal and accordingly determining switched-on or switched-off state and having source connected to a ground voltage; a P type transistor, having source connected to another terminal of the energy-storing inductor, having gate receiving a second driving signal and accordingly determining switched-on or switched-off state and having drain outputting an output voltage; a current comparator, connected to source of the N type transistor so as to receive a sensing current, the current comparator compare the sensing current with a threshold current so as to determine load type and accordingly output a comparison signal; a multiplexer, electrically connected to the current comparator so as to receive the comparison signal, the multiplexer receiving the input voltage and the output voltage and outputting a work voltage according to the comparison signal; a first driver, electrically connected to the multiplexer and the N type transistor, the first driver receiving a pulse width control signal and the work voltage and accordingly outputting the first driving signal, wherein the first driving signal is an oscillation signal and voltage value of high voltage level is equal to voltage level of the work voltage; and a second driver, electrically connected to the P type transistor, the second driver receiving the pulse width control signal and a predetermined DC voltage with high voltage level and accordingly outputting the second driving signal; and wherein when the current value of the sensing current is smaller than the current value of the threshold current, the current comparator outputs the comparison signal with high voltage level, such that the work voltage is equal to the input voltage and voltage level of the second driving signal is equal to the predetermined DC voltage, so as to switch off the P type transistor, wherein a switching current flowing through a parasitic capacitor of the N type transistor is generated from the input voltage; a load, electrically connected to the voltage conversion circuit so as to receive the output voltage.
Specification