近年來,植入式生物醫學裝置被廣泛應用在現代醫學中,如人工視網膜和深腦刺激器。由於植入式裝置必須長期在皮膚下操作,因此,無線電力傳輸系統被廣泛的應用在植入式裝置系統中。 本論文提出一個交流對直流轉換器,結合了全波整流器、高電源抑制線性穩壓器以及內建一個電壓回授控制系統。此電路系統僅需一個小電容便可達到高雜訊抑制的效果,其中高電源抑制線性穩壓器在10 MHz操作頻率下,電源抑制 (Power Supply Rejection, PSR) 效能達到了-43.5dB,在附載切換時的電壓飄移控制在30 mV以下。此外,一組電壓回授控制電路能調便接收端線圈的諧振電容值,避免全波整流器接收到過大的耦合能量造成內部電路損壞,並可提高線性穩壓器的功率轉換效率。 在無線能量傳輸情況下,傳輸距離1 cm時,外部功率放大器可產生足夠的交流能量以電磁耦合方式傳輸至植入端電路,而植入端電路會將所接收到的交流能量透過全波整流器將其轉換為直流,再經由LDO穩壓器穩壓後產生一個穩定的電源供植入端電路使用。而在此同時,一組電壓回授控制電路會判斷所接收到的能量大小並產生不同責任週期 (Duty Cycle) 的PWM (Pulse Width Modulation) 訊號來控制接收端線圈的諧振頻率,藉以調整接收端線圈所得到的能量大小,使植入端電路接收到適當大小的能量,避免電路的損壞。 晶片電路部分使用TSMC 0.18 um 1P6M製程,總面積約為0.383 mm^2 (不包含Pad),操作在10 MHz頻率下可提供一個3.3 V穩定輸出電源,最大附載電流為5 mA。
In recent years, devoted researches of implantable biomedical devices have been studied from modern medicine, such as Artificial Retina and Deep Brain Stimulation. Since the implanted devices operate underneath the skin for a long term, wireless power transmission systems are widely adopted. This thesis presents a wireless power transmission system with a full-wave rectifier, high power supply rejection (PSR) low dropout (LDO) regulator and a voltage feedback control system. The system can provide a stable DC source for implanted devices, and the system only need a small rectification capacitor. The proposed LDO achieves high PSR performance of -43.5 dB at 10 MHz without any external capacitor. Moreover, the power controller is also adopted in the system to feedback control the received power by adjusting resonant capacitance. It help prevent the device from being damaged by excessive power. The circuit is fabricated with the TSMC 0.18 um 1P6M CMOS process and occupies area of 0.383 mm^2. It can provide a stable output voltage of 3.3 V and load current of 5 mA at 10 MHz.