The demand to make the medical devices smaller and smarter, is one of the driving forces of integrated circuits (ICs) and systems. More specifically, the implantable medical devices (IMD’s), which are fully or partially implanted in the human bodies through surgeries, have imposed even critical technical requirements on the building ICs, especially on the wireless connection ICs. A good trade-off has to been made among the key parameters, including the choice of protocols, carrier frequency, data rate, robustness under various interference, etc, and most importantly, the power consumption. In this lecture, the typical medical application scenarios will be discussed, along with a set of miniature IMD’s which have been implemented based the ultra-low power wireless connection. Then the requirement and challenges of wireless connections in such applications will be analyzed, and the design considerations of ultra-low power RF transceivers will be presented. The circuit design details of the recently published 400/915MHz combo transmitter (TX) IC and 915MHz receiver (RX) IC will be presented to demonstrate the above-mentioned design philosophy. The ultra-low power techniques, including the multi-phase digital power amplifier (DPA) based polar TX, the edge combing TX with open-loop local oscillation (LO) generation, and the sub-sampling phase tracking RX will be presented. Through this lecture, we hope that we can share with the audience our thinking and design practice of ultra-low power RF transceivers for miniature medical devices.