US 7,612,613 B2 · Self regulating biasing circuit

Abstract

A disclosed self regulating biasing circuit (SRBC) includes an unregulated node that couples to an unregulated power supply that produces a supply voltage. An impedance element of the SRBC carries an unregulated current having a nominal component and a variance component between an unregulated node and a regulated node. A detection circuit connected between the unregulated node and a third node detects a variance component of a supply voltage and generates a detection current based on the variance component. A compensation circuit connected to the third node draws a compensation current, based on the detection current, from the regulated node. The SRBC is designed wherein the compensation current is approximately equal to the variance component of the unregulated current. The regulated node may be connected to a control terminal of a transistor to be biased.

Claims10

Dependent claims

A power amplifier for use in an RF circuit, comprising:

a power transistor;
a self regulating biasing circuit operable to:
couple to a power supply to receive a supply signal comprising a supply voltage having a nominal component and a variance component and a supply current having a nominal component and a variance component;
and
monitor a first node having a voltage indicative of the supply voltage, generate a detection current based on the monitored voltage, and generate a compensation current based on the detection current, wherein the compensation current is drawn from a control node that receives the supply current;
and
a first resistor connected between the power supply and the first node.

4 more elements

Dependencies are inferred from the claim text.

Self regulating biasing circuit

Life of this patent

Self regulating biasing circuit

Life of this patent

Abstract

Claims10