0.18-V Input Charge Pump with Forward Body Bias to Startup Boost Converter for Energy Harvesting Applications

In this paper, a 0.18-V input three-stage charge pump circuit applying forward body bias is proposed for energy harvesting applications. In the developed charge pump, all the MOSFETs are forward body biased by using the inter-stage/output voltages. By applying the proposed charge pump as the startup in the boost converter, the kick-up input voltage of the boost converter is reduced to 0.18 V. To verify the circuit characteristics, the conventional zero body bias charge pump and the proposed forward body bias charge pump were fabricated with 65 nm CMOS process. The measured output current of the proposed charge pump under 0.18-V input voltage is increased by 170% comparing to the conventional one at the output voltage of 0.5 V. In addition, the boost converter successfully boosts the 0.18-V input to higher than 0.65-V output. key words: charge pumps, switched capacitor, startup, boost converter, low voltage