Enhanced pulse frequency modulation (PFM) control mode for switching regulators
AssigneeQUALCOMM Incorporated
InventorVijayakumar Dhanasekaran
Life of this patent
Estimating the term…
Abstract
A variable supply rail generator is described. The variable supply rail generator includes a regulator configured to use an estimated load current for a power amplifier to optimize efficiency. The variable supply rail generator also includes a power amplifier controller. The power amplifier controller provides the estimated load current to the regulator.
Claims24
A variable supply rail generator, comprising:
- a buck regulator configured to use an estimated load current for a power amplifier to optimize efficiency, wherein the estimated load current comprises a power amplifier current and a filter capacitor current, wherein the buck regulator provides a positive variable supply rail to the power amplifier,
- a negative charge pump, wherein the buck regulator provides a positive variable supply rail to the negative charge pump, and wherein the negative charge pump provides a negative variable supply rail to the power amplifier;
- and,
- a power amplifier controller that provides the estimated load current to the regulator, wherein the power amplifier controller provides a variable frequency clock signal to the negative charge pump that optimizes the power efficiency of the negative charge pump.
The variable supply rail generator of claim wherein the power amplifier current is based on an input voltage, a load resistance and a tolerance, and wherein the filter capacitor current is determined from a rate of change of an envelope.
A method for generating a variable supply rail, comprising:
- receiving an input parameter corresponding to a power amplifier;
- estimating a load current for the power amplifier using the input parameter;
- generating a positive variable supply rail using the estimated load current;
- providing the positive variable supply rail to the power amplifier;
- generating a negative variable supply rail using the estimated load current;
- and
- providing the negative variable supply rail to the power amplifier,
- wherein the positive variable supply rail is generated using a buck regulator,
- wherein the negative variable supply rail is generated using a negative charge pump.
Dependencies are inferred from the claim text.