In recent years , with the rapid development in the Biomedical system and VLSI, the chip circuit applied to medical electronic equipment, not only the implanting types but also the portable ones, has become tinier and tinier.Therefore, low power consumption or power efficiency enhancement is the main concern when designing these portable electronics.
Especially for the implanting chip of high data-rate transmission, such as the cochlear systems, retinal prostheses, by using wireless transmission, the inductive coupling effect can transmit signals of supplying power and controling the chip, which can prevent wound infection and the regular replacement of the half-invading battery by sugery.
In the system, the inductive coupling effect is adopted at the front end to transmit powers and High Data. Therefore, the power contains the AC signal of carrier frequency. The AC signal then can be converted to the DC signal via the full-wave rectifier. Accordingly, as the characteristics of Low Drop-out Regulator(LDO), it stabilizes the output of the DC signal and reduces the power supply ripples.
The circuit structure in this thesis adopts P-Channel MOSFET, an adjustment pass element, to regulate the LDO. Moreover,it enables the Low Dropout regulation system to stabilize at 1.8V and produces load current which is between 0.1mA or 1mA. It also includes push-pull output circuit and other compensating type circuit separately. Besides, the Low Dropout linear regulator undergoes the simulation of ′cic018.l′ process.