US 7,671,674 B2 · Amplifier circuit with automatic gain correction

Abstract

The present invention relates to an amplifier circuit and system, and to a method of compensating a gain imbalance generated in a complementary amplifier stage with first and second amplifier means (22, 24) in a bridge configuration. A compensation offset current is generated in response to the values of input signals supplied to respective inputs of said first and second amplifier means, and the compensation offset current is injected to a junction node between the inputs of the first and second amplifier means (22, 24). Thereby, it can be ensured that the gain of the first and second amplifier means does not depend on the kind of input signals, i.e. balanced or unbalanced input signals. An automatic gain correction can thus be achieved and the requirement of additional control signals or control terminals for selection of gain control circuits depending on the kind of input source or input configuration of the amplifier circuit can be dropped.

Claims10

Dependent claims

An amplifier circuit comprising:

a complementary amplifier stage with first and second amplifier means in a bridge configuration, said first and second amplifier means comprising a first group of input terminals and a second group of input terminals;
and
current generator means for generating a compensation offset current and for injecting said compensation offset current to a junction node between said first group of input terminals of said first and second amplifier means, said current generator means being coupled to said second group of input terminals such that input signals that are supplied to said second group of input terminals of said first and second amplifier means are received by said current generator means;
wherein said current generator means is configured to generate said compensation offset current using the values of the input signals that are supplied to said second group of input terminals of said first and second amplifier means, to balance the outputs of said first and second amplifier means into equal amplitude but opposite polarity.

1 more element

Dependencies are inferred from the claim text.

Amplifier circuit with automatic gain correction

Life of this patent

Amplifier circuit with automatic gain correction

Life of this patent

Abstract

Claims10