Two-phase boosted voltage generator for low-voltage DRAMs

Abstract

A two-phase boosted voltage (V-PP) generator circuit was proposed for use in gigabit DRAMs. It reduced the maximum gate-oxide voltage of pass transistor and the lower limit of supply Voltage to V-PP and V-TN, respectively, while those for the conventional charge-pump circuit are V-PP + V-DD and 1.5 V-TN respectively. Also, the pumping current was increased in the new circuit. The newly proposed two-phase V-PP charge-pump circuit worked successfully at V-DD down to 0.8 V by eliminating the threshold voltage loss of the control pulse generator and was tested successfully in a 0.16-mum test chip using triple-well CMOS technology.