Design considerations for a 1.5-V, 10.7-MHz bandpass gm-C filter in a 0.6-μm standard CMOS technology

A single 1.5 V supply, second order band-pass g_m-C filter based on a low-voltage transconductor architecture in standard 0.6 μm CMOS process is presented. A dc level shifter circuit (DCLS) is utilized at the input of the proposed transconductor to increase the dc level of the input signal. This makes the input transistors operate in the desired region and hence input voltage swing enhances. DCLS uses a simple voltage doubler as its supply while other parts of the circuit use the main 1.5 V supply. Proposed transconductor shows a THD of -60 dB for 1.4 V_pp,diff input signal with 1 MHz frequency. Also a proper common-mode detector circuit is developed for this low-voltage application. The center frequency of the filter is 10.7 MHz and draws less than 45 μA from voltage doubler.