A 170 $\mu\text{A}$ All-Digital GFSK Demodulator With Rejection of Low SNR Packets for Bluetooth-LE

This letter presents an all-digital low-IF Gaussian Frequency-Shift Keying (GFSK) demodulator. The demodulator is based on a quadrature FM discriminator followed by a bit decision unit. An intermediate-frequency (IF) input signal of 1MHz is used, the same value of the data rate, hence allowing a low-power receiver implementation. By monitoring the SNR of the input packet during the preamble, poor SNR packets are discarded to avoid energy waste with non-decodable packets. The circuit occupies a silicon area of 0.048 mm
²
in a 130nm process. Measurements show a state-of-the-art current consumption of about 170 μA from a single 1.2V supply. The proposed demodulator requires an SNR of 14.4 dB for a BER of 0.1%.