An ultralow-power super-regenerative receiver for BFSK modulated signals has been designed and fabricated in a standard 0.18-μm CMOS process. The use of BFSK modulation allows the receiver to operate at higher data rates and also gives an approximate 3-dB SNR performance increase over the more traditional OOK modulation. A fast calibration scheme and the absence of an external inductor make it ideal for ultralow-power sensor networks. A power consumption of 215 μW from a 0.65-V supply and an area of 0.55 mm2 make it ideal for highly integrated energy harvesting sensor nodes. At 2 Mb/s, the receiver consumes 0.18 nJ/b, making it the lowest energy integrated super-regenerative receiver to date.