Wide-band efficiency-enhanced CMOS rectifier

We present in this paper the design of a wide-band efficiency-enhanced CMOS rectifier. A novel semi-active diode is proposed to minimize both the diode forward voltage drop and the reverse leakage current. This is achieved by dynamically configuring the rectification device as a threshold compensated diode in the on-state while a standard MOS diode in the offstate, respectively. The proposed rectifier is implemented in a 0.35μm 4M/2P standard CMOS process. In simulation, with 5.5V AC input at 13.56MHz, the rectifier outputs 4.94V DC voltage across a 1.2kΩ load resistor, achieving 87% power conversion efficiency (PCE) and 90% voltage conversion efficiency (VCE). The PCE and VCE can be maintained from 1MHz to 20MHz input frequency, with only 3% deviation in the PCE and 2% deviation in the VCE. In addition, the performance of the rectifier is self-compensated over temperature and process. From -40°C to +130°C, the simulated VCE varies within 2% from 89.6% to 87.7%, while the PCE stays almost constant at 86%. With 200 Monte Carlo samples, the standard deviation in the PCE and VCE are as low as 0.56% and 0.57%, respectively.