A new dual pumping circuit without body effects for low supply voltage

The new four-phase 4-stage charge pump to generate up to 3.2 V at 1 V supply voltage even with the threshold voltage up to 0.8 V is proposed. We employed a special dual branch substrate connection technique to eliminate the body effect and avoid p-n junction forward conduction. The two-branch structure also provides more stable output loading current than the conventional one branch structure. The 4-stage charge pumps can boost up to 8.8 V and -7 V using PMOS and NMOS transistors, respectively, at 1.8 V supply voltage in the same triple-well technology. The power efficiency could also reach 50% with loading current of 120 /spl mu/A.