A common current source, generally used to bias cross-coupled differential amplifiers in a transconductor, controls third harmonic distortion (HD 3 ) poorly. Separate current sources are shown to provide better control on HD 3 ) . In this paper, a detailed design and analysis is presented for a transconductor made using this biasing technique. The transconductor, in addition, is made to offer high G m , low power dissipation and is designed for linearly tunable G m with current mode load as one of the applications. The circuit exhibits HD 3 ) of less than –43.7 dB, high current efficiency of 1.18 V -1 and G m of 390 μS at 1 VG p-p @ 50 MHz. UMC 0.18 μm CMOS process technology is used for simulation at supply voltage of 1.8 V.
KeywordsAnalog electronicslow power Analog CMOS CircuitOperational Transconductance Amplifier (OTA)Multiple-output OTA (MOTA)MOS Transconductorslinearly tunable G<sub>m</sub>Current efficiencyLinearization TechniquesHarmonic Distortion Analysis
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