RFID Handbook: Fundamentals and Applications in Contactless Smart Cards and Identification
RFID Handbook: Fundamentals and Applications in Contactless Smart Cards and Identification
| Hi-index | 0.00 |
In order to deliver near-field electromagnetic power to a biomedical device or an RFID tag efficiently, the downlink signal is preferred to be at a high voltage level. To reduce power consumption and meet low supply requirements, it is advantageous for the remote device power supply to step-down the input voltage following rectification, typically using switch-mode regulators. The output ripple of a switched capacitor converter is inversely proportional to the filtering capacitance at the output node and switching frequency. In this paper, a hybrid DC---DC converter utilizing a switched capacitor regulator in master---slave configuration with a linear regulator is presented. Linear regulator actively cancels the switching ripple, while low frequency and DC current is provided by the switched capacitor converter. The converter is designed to receive an average input voltage of 5聽Vpk from the receiver coil, with an output voltage of 2聽V, and 5聽mA of output current. The proposed regulator is fabricated in 0.35聽μm technology. The power efficiency is measured to be 67%, with a nominal peak to peak ripple of less than 2聽mV at the output.