Power supply control circuits
AssigneeLattice Semiconductor Corporation
InventorsFrederic N.F. Deboes, Ludmil N. Nikolov, Hans W. Klein, Geoffrey R. Rickard
Life of this patent
Estimating the term…
Abstract
Power supply sequencing systems and methods are disclosed. In one embodiment, a programmable charge pump supplies a programmable current source, which drives an external NFET that controls whether power is supplied to a device or a portion of circuitry. The maximum voltage and the turn-on ramp rate supplied to the NFET are programmable and, therefore, the NFET can be operated safely within its rated limits without requiring external protection devices. If a high-voltage output terminal is not required to drive an external NFET, the output terminal, in accordance with another embodiment, may be configured to function as an open drain logic output terminal.
Claims32
A circuit comprising:
- a regulated boost supply adapted to provide a programmable supply voltage;
- and
- a current source, coupled to the regulated boost supply, adapted to receive the programmable supply voltage and provide a programmable current.
A method of switching a transistor for power sequencing applications, the method comprising:
- providing a programmable voltage that determines a desired voltage applied to a gate terminal of the transistor;
- and
- providing a programmable current that receives the programmable voltage and determines a desired voltage ramp rate at the gate terminal of the transistor.
A power sequencing circuit comprising:
- a regulated boost supply adapted to provide a programmable voltage that determines a desired voltage applied to a gate terminal of a transistor;
- a current source, coupled to the regulated boost supply, adapted to receive the programmable voltage and provide a programmable current that determines a desired voltage ramp rate at the gate terminal of the transistor;
- and
- a current sink, coupled to the current source, adapted to selectively discharge the gate terminal of the transistor.
A circuit comprising:
- means for providing a programmable voltage that determines a desired voltage applied to a gate terminal of a transistor;
- and
- means for receiving the programmable voltage and providing a programmable current that determines a desired voltage ramp rate at the gate terminal of the transistor.
A circuit comprising:
- a regulated boost supply adapted to provide a supply voltage;
- and
- a current source, coupled to the regulated boost supply, adapted to receive the supply voltage and provide a programmable current.
A circuit comprising:
- a regulated boost supply adapted to provide a programmable supply voltage;
- and
- a current source, coupled to the regulated boost supply, adapted to receive the programmable supply voltage and provide a current.
A circuit comprising:
- a regulated boost supply adapted to provide a supply voltage, the boost supply including a feedback loop responsive to a reference voltage for maintaining a desired setting for the supply voltage;
- and
- a current source, coupled to the regulated boost supply, adapted to receive the supply voltage and provide a current.
A circuit comprising:
- a regulated boost supply adapted to provide a supply voltage;
- and
- a current source, coupled to the regulated boost supply, adapted to receive the programmable supply voltage and a reference current and provide an output current that is a multiple of the reference current.
Dependencies are inferred from the claim text.