Voltage regulator incorporating configurable feedback and source follower outputs
AssigneeCrosspoint Solutions, Inc.
InventorGary L. Allman
Life of this patent
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Abstract
A voltage regulator especially adaptable for use with field-programmable gate arrays (FPGAs). The voltage regulator includes a frequency compensated differential amplifier, a configurable feedback network for setting the gain of the voltage regulator, and a plurality of source follower devices for driving the feedback network and providing a regulated supply voltage. A bandgap generator may also be provided for generating a reference bias voltage that is independent of temperature.
Claims10
In a semiconductor circuit having a plurality of circuit elements, a voltage regulator comprising:
- a frequency compensated differential amplifier for generating a regulated voltage and having paired first and second self-biased input cascode transistors;
- a configurable resistive feedback network for setting the gain of said voltage regulator;
- and
- a plurality of source follower devices connected in parallel for buffering the output of said amplifier;
- a first of said source follower devices adapted for driving said feedback network and the remaining source follower devices adapted for providing a regulated supply voltage to said circuit elements.
In a semiconductor device having a plurality of core logic elements, a circuit for generating a regulated power supply voltage substantially independent of an external power supply comprising:
- a differential amplifier having self-biasing input pair cascode transistors, a feedback network for setting the gain of said amplifier coupled to one input of said amplifier, a plurality of source follower devices for buffering the output of said amplifier, one of said source follower devices adapted for driving said feedback network and the remaining source follower devices adapted for providing a regulated supply voltage to said semiconductor device, and a frequency compensation capacitor coupled between the output of said amplifier and the ground reference;
- and
- a bandgap generator for generating a reference bias voltage coupled to another input of said amplifier;
- said bandgap generator having a proportional- to-absolute temperature voltage source for generating a substantially temperature-independent reference bias voltage.
In a semiconductor device having a plurality of logic elements, a circuit for generating a regulated power supply voltage substantially independent of an external power supply comprising:
- a differential amplifier having self-biasing input pair cascode transistors, a configurable resistive feedback network for setting the gain of said amplifier coupled to one input of said amplifier, a plurality of source follower devices for buffering the output of said amplifier, one of said source follower devices adapted for driving said feedback network and the remaining source follower devices adapted for providing a regulated supply voltage to said logic elements, and a frequency compensation capacitor coupled between the output of said amplifier and the ground reference;
- and
- a bandgap generator for generating a reference bias voltage coupled to another input of said amplifier, said reference bias voltage having a positive temperature dependence;
- whereby said logic elements maintain a constant switching speed as temperature increases.
Dependencies are inferred from the claim text.