Power converter having charge pump frequency switching control mechanism
A power converter having a charge pump frequency switching control mechanism is provided. In the power converter, frequencies of a plurality of pulse waves of a clock signal are determined, according to a level of a high-side control signal outputted to a control terminal of a high-side switch from a control circuit or a voltage of the control terminal (and a voltage of a second terminal) of the high-side switch. In the power converter, a charge pump supplies power to a high-side driver circuit at the frequencies of the clock signal, and the high-side driver circuit uses the power from the charge pump to drive the high-side switch and to pull up the voltage of the control terminal of the high-side switch.
1. A power converter having a charge pump frequency switching control mechanism, comprising:
a high-side switch, wherein a first terminal of the high-side switch is connected to an input voltage source;
a low-side switch, wherein a first terminal of the low-side switch is connected to a second terminal of the high-side switch, and a second terminal of the low-side switch is grounded;
a control circuit configured to output a high-side control signal and a low-side control signal;
a low-side driver circuit connected to a control terminal of the low-side switch and the control circuit, and configured to output a low-side driving signal to the control terminal of the low-side switch according to the low-side control signal from the control circuit;
a high-side driver circuit connected to a control terminal of the high-side switch and the control circuit, and configured to output a high-side driving signal to the control terminal of the high-side switch according to the high-side control signal from the control circuit;
a pulse signal generator circuit connected to the control circuit, configured to determine whether to generate a pulse wave in a high-side pulse enable signal according to a level of the high-side control signal from the control circuit, and configured to output the high-side pulse enable signal;
a clock generator circuit connected to the pulse signal generator circuit, configured to determine whether or not the pulse wave is in the high-side pulse enable signal to determine a frequency of a clock signal, and configured to output the clock signal; and
a charge pump connected to the clock generator circuit and the high-side driver circuit, wherein the charge pump determines a frequency of supplying power to the high-side driver circuit according to the frequency of the clock signal from the clock generator circuit, and the charge pump charges the high-side driver circuit to supply the power required for the high-side driver circuit to drive the high-side switch and to pull up a voltage of the control terminal of the high-side switch.
2. The power converter according to claim 1 , wherein the charge pump outputs a charging signal to the high-side driver circuit, the high-side driver circuit uses power of the charging signal from the charge pump to pull up the voltage of the control terminal of the high-side switch from an initial voltage to be higher than an input voltage of the input voltage source and to reach a voltage of the charging signal.
3. The power converter according to claim 1 , wherein, when the control circuit outputs the high-side control signal at a low level respectively to the pulse signal generator circuit and the high-side driver circuit, the pulse signal generator circuit outputs the high-side pulse enable signal at a low level to the clock generator circuit according to the high-side control signal at the low level, and the clock generator circuit outputs the clock signal having a low frequency to the charge pump according to the high-side pulse enable signal at the low level.
4. The power converter according to claim 3 , wherein, when the control circuit outputs the high-side control signal at a high level respectively to the pulse signal generator circuit and the high-side driver circuit, the pulse signal generator circuit outputs the high-side pulse enable signal having the pulse wave to the clock generator circuit according to the high-side control signal at the high level, and the clock generator circuit outputs the clock signal having a high frequency to the charge pump according to the high-side pulse enable signal having the pulse wave.
5. The power converter according to claim 1 , wherein, the frequency of the clock signal that is outputted by the clock generator circuit within time other than a working period of the pulse wave of the high-side pulse enable signal is equal to a first reference frequency;
wherein the frequency of the clock signal that is outputted by the clock generator circuit within the working period of the pulse wave of the high-side pulse enable signal is equal to a second reference frequency;
wherein the second reference frequency is higher than the first reference frequency.
6. The power converter according to claim 1 , wherein the charge pump includes:
a first capacitor, wherein a first terminal of the first capacitor is connected to the input voltage source and the high-side driver circuit, and a second terminal of the first capacitor is grounded.
7. The power converter according to claim 6 , wherein the charge pump further includes:
a second capacitor, wherein a first terminal of the second capacitor is connected to the input voltage source, and a second terminal of the second capacitor is connected to the first terminal of the first capacitor.
8. The power converter according to claim 7 , wherein the charge pump further includes:
a first switch component, wherein a first terminal of the first switch component is connected to the input voltage source, a second terminal of the first switch component is connected to the first terminal of the second capacitor, and a control terminal of the first switch component is connected to an output terminal of the clock generator circuit.
9. The power converter according to claim 8 , wherein the charge pump further includes:
a second switch component, wherein a first terminal of the second switch component is connected to the second terminal of the second capacitor, a second terminal of the second switch component is connected to the first terminal of the first capacitor, and a control terminal of the second switch component is connected to the output terminal of the clock generator circuit.
10. The power converter according to claim 9 , wherein the charge pump further includes:
a third switch component, wherein a first terminal of the third switch component is connected to the input voltage source, a second terminal of the third switch component is connected to the second terminal of the second capacitor, and a control terminal of the third switch component is connected to the output terminal of the clock generator circuit.
11. The power converter according to claim 10 , wherein the charge pump further includes:
a fourth switch component, wherein a first terminal of the fourth switch component is connected to the first terminal of the second capacitor, a second terminal of the fourth switch component is coupled to a reference voltage, and a control terminal of the fourth switch component is connected to the output terminal of the clock generator circuit.