A Wireless Power Management Unit with a Novel Self-Tuned LDO for System-On-Chip Sensors

A wireless power management unit is presented in this work. The system size of 0.4mm
²
with the low power consumption of 87μW allow it to be applied in implantable biomedical applications and ex-vivo systems. The proposed system optimises the conventional slew-rate detection low dropout (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 (BGR) 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 and the internal power management circuit is able to provide a 1.4V stable DC supply for a front end on-chip sensor.