Bootstrap circuit
AssigneeTexas Instruments Incorporated
InventorsMaik Peter Kaufmann, Stefan Herzer, Michael Lueders
Life of this patent
Estimating the term…
Abstract
In one example, an apparatus comprises: a first transistor having a first control terminal and first and second current terminals; a capacitor coupled between a switching terminal and the first current terminal; a second transistor having a second control terminal and coupled between the switching terminal and a ground terminal; and a sensing and control circuit having a power terminal, a third current terminal, an enable input and a transistor control output, the third current terminal coupled to the second current terminal, the enable input coupled to the second control terminal, and the transistor control output coupled to the first control terminal.
Claims20
An apparatus comprising:
- a first transistor having a first control terminal and first and second current terminals;
- a capacitor coupled between a switching terminal and the first current terminal;
- a second transistor having a second control terminal and coupled between the switching terminal and a ground terminal;
- and
- a circuit having a power terminal, a third current terminal, an enable input, and a transistor control output, the third current terminal coupled to the second current terminal, the enable input coupled to the second control terminal, and the transistor control output coupled to the first control terminal, the circuit configurable to set a state of the transistor control output responsive to at least one of:
- a current between the power terminal and the third current terminal and through the first transistor, or a voltage at the first control terminal.
A system comprising:
- a first transistor coupled between a power input and a switching terminal, the first transistor having a first transistor control input;
- a second transistor coupled between the switching terminal and a ground terminal, the second transistor having a second transistor control input;
- a first driver having a first driver output, a first power supply terminal, and a first reference terminal, the first driver output coupled to the first transistor control input, and the first reference terminal coupled to the switching terminal;
- a capacitor coupled between the first power supply terminal and the first reference terminal;
- a second driver having a second driver output, a second power supply terminal, and a second reference terminal, the second driver output coupled to the second transistor control input, and the second reference terminal coupled to the ground terminal;
- a circuit having a power terminal, a current terminal, an enable input and a transistor control output, the power terminal coupled to the second power supply terminal, and the enable input coupled to the second transistor control input, the circuit configurable to set a state of the transistor control output responsive to at least one of:
- a current between the power terminal and the current terminal, or a voltage at the transistor control output;
- and
- a third transistor coupled between the current terminal and the first power supply terminal, the third transistor having a third transistor control input coupled to the transistor control output.
A method comprising:
- receiving a low side (LS) switch enable signal that controls a low side switch;
- responsive to the LS switch enable signal having a first state, setting a voltage on a control terminal of a transistor based on sensing a current from a power source through the transistor to a capacitor coupled between the transistor and the low side switch;
- and
- responsive to the LS switch enable signal having a second state, disabling the transistor to disconnect the capacitor from the power source.
Dependencies are inferred from the claim text.