CMOS Integrated Active Rectifier with Temperature Independent Efficiency

This paper presents a highly efficient fully CMOS integrated active rectifier for telemetric energy transmission or as interface for energy harvesters. The rectifier is implemented using a standard 0.35 ¿m CMOS process without special process options. Compared to other solutions no start-up circuit and only one current consuming comparator is needed to realize a full wave rectifier. Measurements show a negligible serial voltage drop, high output power and efficiency. The input voltage range is between 1.25 and 3.75 V and the current consumption is 1.2¿A@2V. The maximum input frequency is over 2.5MHz@3.5V input amplitude. Temperature measurements between -40 to+125°C show a temperature stable output voltage.