A 0.06–3.4-MHz 92-$\mu$ W Analog FIR Channel Selection Filter With Very Sharp Transition Band for IoT Receivers

Analog FIR filtering is proposed to improve the performance of a single stage ${g}_{m}$ -C channel selection filter for ultra low power Internet-of-Things receivers. The transconductor is implemented as a digital-to-analog converter; allowing a varying transconductance in time, which results in a very sharp FIR filter. The filter is manufactured in 22-nm FDSOI and has a core area of 0.09 mm2. It consumes 92 $\mu \text{W}$ from a 700-mV supply and achieves $f_{-60\,\,\mathrm {dB}}/f_{-3\,\,\mathrm {dB}}=3.8$ . The filter has 31.5 dB gain, out-of-band OIP3 of 28 dBm and output referred 1-dB compression point of 3.7 dBm. The filter bandwidth is tunable from 0.06 to 3.4 MHz.