Presented is a frequency-translation technique for compact realization of a low-noise lowpass filter (LPF) for biopotential acquisition systems. It is by chopper-stabilizing a bandpass filter (BPF) to obtain an ultra-low-cutoff lowpass response. This technique not only removes the BPF's flicker noise and dc-offset, but also adds clock-based gain-bandwidth tunability and saves chip area because of highly relaxed time constants. A 1.4 to 15-Hz 2nd-order OTA-C ladder LPF designed in a 90-nm CMOS process verifies the merits of the technique with respect to the prior art. © 2012 Springer Science+Business Media, LLC.