A compact and low-power wireless receiver supporting 2.4 GHz industrial, scientific and medical (ISM) band is implemented in a 130 nm Complementary Metal–Oxide–Semiconductor (CMOS) process. The GHz operating frequency renders the chip to be matched with a mm-sized antenna to reduce implants’ size and improve patients’ experience. To simplify the implanted chip, the downlink is through On-Off Keying (OOK) so non-coherent detection and simplified receiver chain can be deployed. Boosted Rectifier and open-loop amplifier-based receiver chain lowers the chip’s power consumption to nW level. The measured sensitivity reaches −50 dBm at a Bit Error Rate (BER) of 1e-3.