US 2006/0220742 A1 · Circuit and method for automatic gain control

Abstract

A system for generating a supply voltage, temperature and process compensated gain control voltage from a digital data word. In particular, the compensated gain voltage control voltage maintains a linear relationship between a change in gain in response to an input gain control voltage for a gain circuit of a transmitter circuit. A monitor circuit senses at least one of the supply voltage, temperature and process parameters, and generates a first set of digital signals corresponding to the sensed parameter. A digital compensator circuit converts the input gain control voltage into a second set of digital signals, and decodes the combined first and second set of digital signals to provide a data word. The data word is converted into an analog voltage representing the compensated gain voltage control voltage. The digital compensator circuit includes a table of compensation values, each accessible by a distinct combination of the first and second set of digital signals.

Claims25

Dependent claims

A voltage generating circuit for providing an output voltage corresponding to an input voltage and at least one measurable parameter, comprising:

a monitor circuit for sensing the at least one measurable parameter, and converting said at least one measurable parameter into an offset address;
and, a digital compensator circuit for receiving the input voltage and the offset address, the digital compensator circuit converting the input voltage into a base address, the digital compensator circuit providing a data word addressable by a combination of the base address and the offset address, the digital compensator circuit including a D/A converter for converting the data word into the output voltage.

An automatic gain control circuit for generating a compensated voltage gain signal in response to a control voltage, comprising:

a first parameter measuring circuit for providing a first voltage;
a second parameter measuring circuit for providing a second voltage;
a conversion circuit for selectively receiving the first and the second voltages, the converting circuit converting the first voltage into a first portion of the offset address and the second voltage into a second portion of the offset address;
latching means for latching the first portion of the offset address and the second portion of the offset address, the latching means aggregating the first and the second offset addresses into an offset address;
an analog-to-digital converter for receiving the control voltage and converting said control voltage into a base address;
and,
a digital compensator circuit for receiving the base address and the offset address, the digital compensator circuit generating the compensated voltage gain signal from a data word corresponding to a combination of the base address and the offset address.

4 more elements

Dependencies are inferred from the claim text.

Circuit and method for automatic gain control

Life of this patent

Circuit and method for automatic gain control

Life of this patent

Abstract

Claims25