Self-bootstrap driving circuit and DC-DC converter
View Patent ↗A self-bootstrap driving circuit includes a first input receiving a first control signal; an output, to which a load having an electro-inductive component may be connected; a power switch having first and second current terminals and a control terminal, and being arranged to drive power from a power supply terminal to the load; a bootstrap circuitry arranged to drive the control terminal of the power switch based on the control signal; and a current path between the electro-inductive component of the load and the control terminal of the switch, said current path being arranged to provide direct transfer from said electro-inductive component to said control terminal of the switch of an overvoltage generated at the electro-inductive component to provide an overdrive voltage to said control terminal of the switch.
1. A self-bootstrap driving circuit comprising:
a first input receiving a first control signal;
an output, to which a load having an electro-inductive component may be connected;
a power switch having first and second current terminals and a control terminal, and being arranged to drive power from a power supply terminal to the load;
a bootstrap circuitry arranged to drive the control terminal of the power switch based on the control signal;
a current path between the electro-inductive component of the load and the control terminal of the switch, said current path being arranged to provide direct transfer from said electro-inductive component to said control terminal of the switch of an overvoltage generated at the electro-inductive component to provide an overdrive voltage to said control terminal of the switch.
2. The driving circuit of claim 1 , further comprising a clamping circuitry arranged to clamp the overdrive voltage to a given clamping threshold.
3. The driving circuit of claim 2 , wherein the clamping circuitry is coupled to the control terminal of the power switch.
4. The driving circuit of claim 2 , wherein the clamping circuitry comprises a Zener diode.
5. The driving circuit of claim 2 , further comprising:
a clamp detection circuitry arranged for detecting that the voltage at the control terminal of the power switch is clamped to the clamping threshold; and,
a first control switch arranged in series within the current path, the clamp detection circuitry being arranged to control the opening of the control switch responsive to the voltage at the control terminal of the power switch being clamped to the clamping threshold.
6. The driving circuit of claim 1 , wherein the power switch is a high-side or high side configured switch.
7. The driving circuit of claim 1 , wherein the power switch comprises a power MOSFET.
8. The driving circuit of claim 1 , wherein the current path comprises at least one of the following components connected in series within said current path: a diode with an anode terminal turned to the output of the electro-inductive component and a cathode terminal turned to the control terminal of the power switch, a controlled switch, a capacitor, and a resistor.
9. The driving circuit of claim 1 , further comprising a start-up circuitry arranged for providing a current to the electro-inductive component during an initialization phase.
10. The driving circuit of claim 1 , further comprising at least a second controlled switch in series with the electro-inductive component of the load, and controlled to be open to generate the overvoltage at an output of said electro-inductive component.
11. A DC-DC converter comprising at least one inductor and a driving circuit as claimed in claim 1 , arranged to drive at least one load having said inductor as the electro-inductive component.
12. The DC-DC converter of claim 11 , having a Single Inductor Multiple Output, SIMO, topology.