A linear compact tunable transconductor for Gm-C applications

Abstract

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-lm CMOS technology feature a spuriousfree 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.

Analog Continuous-Time Filter Designing for Morlet Wavelet Transform Using Constrained L2-Norm Approximation

“…For example, in [11], [21] and [22], ultra-low power Gm-C filter is applied for biomedical signal processing. In [23], [24] and [25], the linearization technique for the transconductor is studied to increase the linear range of Gm-C filter. In [26] and [27], filter topology is analyzed to implement the filter into a linear system.…”

A new controllable adaptive biasing linearization technique for a CMOS OTA and its application to tunable Gm-C filter design

“…This becomes more challenging by taking into account that in most applications the linearity enhancement is required in a wide range of transconductances. Moreover, employed technique for linearization should neither increase noise and power consumption nor decrease total achievable transconductance (G m ) [10,[30][31][32][33].…”