A linear compact tunable transconductor for Gm-C applications
A CMOS highly linear voltage-controlled transconductor suitable for Gm-C filter design is presented. The control loop to program the transconductance maintains the input transistors in triode region with a compact topology. Measurement results for the transconductor fabricated in a 0.5-mu m CMOS technology feature a spurious-free dynamic range (SFDR) of 72 dB for 1 V-pp differential inputs at 1 MHz. The voltage to current converter ensures a high linearity level for a wide transconductance range. Functionality of the transconductor is shown in a fifth-order Gm-C tunable complex filter well suited for a dual-mode Bluetooth/Zigbee transceiver.
linearity transconductor channel filter communication receiver