| 摘要 |
An operational amplifier is provided with an extended common mode input range. This operational amplifier includes an input stage, a common mode feedback circuit, a current mirror, a replica input stage, and an output stage. The input stage couples to the CMFB circuit and replica input stage. The input stage is operable to receive a feedback signal from the CMBF circuit. This feedback signal is based on comparing a common mode voltage to a common mode reference voltage. The current mirror, coupled to the CMFB circuit and input stage, mirrors currents within the input stage as input to the CMFB circuit. The replica input stage, which is also coupled to the CMFB circuit, uses an input common mode (INCM) voltage to adjust current flow within the replica input stage. This allows a current within the CMFB circuit to be a function of the INCM. The output stage couples to the input stage and is operable to provide an amplified signal corresponding to a first differential signal.
|
