ELECTRONIC CIRCUIT COMPRISING A DIFFERENTIAL PAIR PROVIDED WITH DEGENERATION MEANS FOR DEGENERATING A TRANSCONDUCTANCE OF THE DIFFERENTIAL PAIR

摘要

An electronic circuit includes a differential pair (T1, T2) provided with a degeneration device (DGMNS) for degenerating a transconductance of the differential pair (T1, T2), and an auxiliary circuit (B) for supplying a control voltage (U) to a control terminal (CNTRL) of the degeneration device (DGMNS). The auxiliary circuit (B) also accomplishes a DC-biasing of the differential pair (T1, T2). The control voltage (U) and the DC-biasing are such that the transconductance of the differential pair (T1, T2) is virtually independent of the value of the control voltage (U) and virtually independent of the DC-biasing of the differential pair (T1, T2). The auxiliary circuit (B) comprises a further differential pair (T3, T4) provided with a further degeneration device (FDGMNS) for degenerating a transconductance of the further differential pair (T3, T4). The auxiliary circuit (B) is arranged for supplying a further control voltage (UF) to a control terminal (FCNTRL) of the further degeneration device (FDGMNS). The control voltage (U) is dependent on the further control voltage (UF). The further control voltage (UF) and the control voltage (U) can, for instance, be the same voltage. The auxiliary circuit (B) includes a device (B2) for generating a desired current ratio (n) between a first branch (Br1) and a second branch (Br2) of the further differential pair (T3, T4). The auxiliary circuit (B) includes a device (B1) for generating a first DC-voltage (VP) to a first input terminal of the further differential pair (T3, T4), and a second DC-voltage (VM) to a second input terminal of the further differential pair (T3, T4).