US Patent 7590017 DRAM bitline precharge scheme

Circuits and method for precharging a pair of complementary bitlines in a dynamic random access memory (DRAM). Both bitlines are precharged to VDD during a precharge phase, and during a sensing phase, the voltage of one of the pair of complementary bitlines is adjusted from VDD to a reference level. The reference level is generated by coupling the one of the pair of complementary bitlines to a capacitance means located within a reference voltage circuit. The reference voltage circuit can include one capacitor element or a plurality of capacitor elements connected in parallel with each other. Any number of the plurality of capacitor elements can be selectively enabled.