Electronic device and method for DC-DC conversion
View Patent ↗An electronic device for driving a power switch coupled to receive a first supply voltage level at one side of its channel is provided. The electronic device includes a control switch coupled with a first side of a channel to receive a varying control voltage having a maximum level that is greater than a maximum voltage level of the first voltage supply and with another side of the channel to a control gate of the power switch for selectively applying the control voltage to the control gate of the power switch. The first side of the channel is coupled with the control gate of the control switch and a capacitor is provided and coupled with a first side to the control gate of the control switch and with a second side to a constant voltage supply.
1. An electronic device for driving a power switch coupled to receive a first supply voltage level at one side of its channel, the electronic device comprising:
a control switch coupled with a first side of a control switch channel to receive a varying control voltage having a maximum level that is greater than a maximum voltage level of the first voltage supply and with another side of the channel to a control gate of the power switch for selectively applying the control voltage to the control gate of the power switch; and
a diode coupled with a cathode to the first side of the control switch channel and with an anode to the control gate of the control switch,
wherein the first side of the control switch channel is coupled with a control gate of the control switch and a biasing capacitor is provided and coupled with a first side to the control gate of the control switch and with a second side to a constant voltage supply.
2. The electronic device according to claim 1 , wherein the diode is a Zener diode having a breakthrough voltage equal to or lower than the maximum admissible voltage drop between the first side of the channel and the control gate of the control switch.
3. The electronic device according to claim 1 , further comprising a series of diodes coupled between the first side of the channel and the control gate in forward biased direction and being configured to provide a voltage drop between the first side of the channel and the control gate of the control switch equal to or lower than the maximum admissible voltage drop between the first side of the channel and the control gate of the control switch.
4. The electronic device according to claim 1 , further comprising a first resistor coupled between the control gate of the control switch and the first side of the capacitor.
5. The electronic device according to claim 4 , further comprising a second resistor coupled between the control gate of the control switch and the first side of the channel being configured to close the control switch in DC operation.
6. The electronic device according to claim 1 , further comprising a diode coupled to receive a second supply voltage level at an anode and being coupled with a cathode to the first side of the capacitor.
7. The electronic device according to claim 1 , further comprising a diode coupled to receive a second supply voltage level at an anode and being coupled with a cathode to the first side of the channel of the control switch.
8. A method of driving a power switch of a DC-DC converter, the method comprising:
selectively applying a maximum voltage level of a control voltage that is greater than a maximum level of a first voltage supply to a control gate of the power switch with a control switch coupled with a channel to the control gate of the power switch;
wherein a control gate of the control switch is coupled to a first side of a biasing capacitor which is coupled with a second side to a constant voltage supply;
coupling the channel of the control switch to a bootstrap capacitor for receiving a control signal from the bootstrap capacitor and wherein the biasing of the gate of the control switch is set by an RC passive network, including the biasing capacitor.
9. The method of claim 8 , wherein the control switch is a PMOS transistor having its source coupled to a positive node of the bootstrap capacitor.
10. An electronic device for driving a power switch coupled to receive a first supply voltage level at one side of its channel, the electronic device comprising:
a control switch coupled with a first side of a control switch channel to receive a varying control voltage having a maximum level that is greater than a maximum voltage level of the first voltage supply and with another side of the channel to a control gate of the power switch for selectively applying the control voltage to the control gate of the power switch;
wherein the first side of the control switch channel is coupled with a control gate of the control switch and a biasing capacitor is provided and coupled with a first side to the control gate of the control switch and with a second side to a constant voltage supply, and wherein the channel of the control switch is coupled to a bootstrap capacitor for receiving a control signal from the bootstrap capacitor and wherein the biasing of the gate of the control switch is set by an RC passive network, including the biasing capacitor.
11. The device of claim 10 , wherein the control switch is a PMOS transistor having its source coupled to a positive node of the bootstrap capacitor.
12. The electronic device according to claim 10 , further comprising a diode coupled with a cathode to the first side of the control switch channel and with an anode to the control gate of the control switch.
13. The electronic device according to claim 10 , wherein the diode is a Zener diode having a breakthrough voltage equal to or lower than the maximum admissible voltage drop between the first side of the channel and the control gate of the control switch.
14. The electronic device according to claim 10 , further comprising a series of diodes coupled between the first side of the channel and the control gate in forward biased direction and being configured to provide a voltage drop between the first side of the channel and the control gate of the control switch equal to or lower than the maximum admissible voltage drop between the first side of the channel and the control gate of the control switch.
15. The electronic device according to claim 10 , wherein the RC passive network comprises a first resistor coupled between the control gate of the control switch and the first side of the capacitor.
16. The electronic device according to claim 15 , further comprising a second resistor coupled between the control gate of the control switch and the first side of the channel being configured to close the control switch in DC operation.
17. The electronic device according to claim 10 , further comprising a diode coupled to receive a second supply voltage level at an anode and being coupled with a cathode to the first side of the capacitor.
18. The electronic device according to claim 10 , further comprising a diode coupled to receive a second supply voltage level at an anode and being coupled with a cathode to the first side of the channel of the control switch.