A digital multilevel memory system includes a charge pump and a voltage
regulator for generating regulated high voltages for various memory
operations. The charge pump may include a plurality of boost circuits to
boost the output of the charge pump during a fast start up. Afterwards,
the boost circuits are disabled to allow the charge pump to generate high
voltages without boosting. The boost circuits may be successively enabled
to boost the voltage. The boost circuits may be loadless. The voltage
regulator may operate in an open loop and may include a resistive divider
as a reference voltage for regulating the high voltage from the charge
pump. The charge pump may include spread spectrum pump clocking to reduce
electromagnetic inference for capacitor or inductor on-chip charge
pumping.