Patent ID: 6538510
Filing Date: 2003-03-25
Classification: H03F,H04L

Abstract:
A line driver output stage, comprising:a first amplifier comprising a series combination of a first semiconductor device and a second semiconductor device; a second amplifier comprising a series combination of a first semiconductor device and a second semiconductor device; a first transformer in parallel with the first semiconductor device of the first amplifier; a second transformer in parallel with the first semiconductor device of the second amplifier; a first back-matching resistor network interposed between the first and the second semiconductor device of the first amplifier, the first back-matching resistor network coupled to a supply voltage, the first semiconductor device of the first amplifier, and a first primary terminal of a first transformer at a first node, the first back-matching resistor network further coupled to a second terminal of a first transformer and a second node interposed between the first and the second semiconductor devices of the first amplifier; and a second back-matching resistor network interposed between the first and the second semiconductor device of the second amplifier, the second back-matching resistor network coupled to the supply voltage, the first semiconductor device of the second amplifier, and a first primary terminal of a second transformer at a third node, the second back-matching resistor network further coupled to a second terminal of a second transformer and a fourth node interposed between the first and the second semiconductor devices of the second amplifier.