摘要 |
Methods, circuits and apparatus for biasing an amplifier to maintain consistent operational characteristics over variations in fabrication processes and operational temperature conditions are disclosed. A bias is determined by first comparing output voltages of replica circuits of the amplifier during an offset canceling phase. The output voltages are differently driven by an offset induced by a first reference current and the offset is canceled in response to the first comparing step. The output voltages are secondly compared during a calibration phase and a calibration bias current is adjusted in response to the second comparing step. The amplifier bias is determined based on the calibration bias current. The process is periodically repeated in response to operational variations.
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