A PVT tolerant BPF using turn-off MOSFET for bio applications in 0.13μm CMOS

This paper presents a PVT tolerant BPF for bio-medical applications, which operate at very low frequencies. As the BPF used in this area has a very large time constant, the cut-off frequency of the BPF is very susceptible to PVT variations. In order to avoid such variation, the proposed architecture uses a replica LPF and negative feedback to enable a PVT invariant time constant. Simulation result shows that the variation of the frequency response of the proposed BPF remains under 1% with the following PVT variations: process (ss, tt, ff), voltage (1.1V to 2.0V) and temperature (0°C to 100°C). The circuit has been implemented using 0.13μm CMOS technology with a supply voltage of 1.2V and 3.3V and it consumes 200nW.