| 摘要 |
Systems and methods for providing a fully differential amplifier performing common-mode voltage control having reduced area and power requirements are disclosed. The amplifier (A1) disclosed comprises an additional input stage (30) at the amplifier input which senses the common mode voltage of the amplifier's inputs and applies internal feedback control (Zfbkp, Zfbkn) to adjust the output common-mode voltage until the input common-mode voltage matches a target voltage (Vcmref) and thereby indirectly set the output common-mode voltage. Furthermore the internal common-mode control can be implemented in such a manner as to provide a feed-forward transconductance function in addition to common-mode control if desired. Moreover it is possible to use feedback from other amplifier stages in an amplifier chain to implement common-mode feedback. |
