A wireless power management unit is presented in this work. The unit’s small size of 0.4mm2 and low power consumption of 87µW allow it to be applied in implanted biomedical applications and ex-vivo systems. The proposed system optimises the conventional slew-rate detection low drop-out (LDO) circuit by using a self-tuned controlling block that reduces the response time to 100ns. The static power required for this LDO is reduced to 2µW. The Band Gap Reference is designed with a high power supply rejection ratio (PSRR) of 60dB at 100kHz, along with an output reference voltage deviation of 1mV, to deal with the power supply ripple caused by the load shift keying (LSK). The RF power is transmitted at 433MHz with a backscattering data rate up to 300kHz. The internal power management circuit provides a 1.4V stable DC supply for a front end electro-chemical Sensor up to a maximum power consumption of 87µW.