We have designed the complete electronic system for an implanted sensory NFC-A tag (type 1) that monitors a physiological parameter, e.g. blood glucose, dehydration, bladder pressure, to name some of the target applications that we pursue. The tag is meant to be implanted under the skin and is powered by an NFC reader held close to it, such as a smart phone or a smart watch. The electronic system consists of a sensor front-end, ADC, NFC-A transceiver and NFC power harvester. In its present status, the physical layer of the communication and the power harvester have been implemented on one ASIC, and the sensor front-end and ADC on another, while the digital circuits realizing the higher level NFC protocol have been implemented on an FPGA. Simulations and a few preliminary test results are presented in this paper. The ultimate goal after thorough testing of this first prototype is to integrate all of these modules on a single ASIC.