Patent ID: 8841970
Filing Date: 2014-09-23
Classification: H03F

Abstract:
1. An apparatus comprising: an operational amplifier configured to set a gate voltage of an input transistor to generate a current, the current comprising a component proportional to an input voltage minus a reference voltage; a resistor coupling the input voltage to an input of the operational amplifier, the resistance of the resistor defining the proportionality between the component current and the input voltage minus the reference voltage; and a current replication module configured to replicate the current at a 1:N ratio to generate a transconductance current proportional to the input voltage, the current replication module comprising: a first transistor having a predetermined size ratio relative to the input transistor, the gate voltage of the input transistor being coupled to the gate voltage of the first transistor; the transconductance current being derived from the drain current of the first transistor; and the current of the input transistor further comprising an input bias current, the first transistor being biased by a first bias current, the first bias current having the same predetermined size ratio relative to the input bias current as the first transistor has relative to the input transistor.