A charge pump that generates positive and negative high voltages with low power-supply voltage and low power consumption for non-volatile memories

A charge pump that generates positive and negative high voltages with low power-supply voltage and low power consumption was developed. By controlling the body and gate voltage of each transfer HVNMOS, high output voltage can be obtained from a low power-supply voltage. For low power consumption, the clock frequency of the charge pump is varied according to its output voltage. Output voltages of a seven-stage negative charge pump and a five-stage positive charge pump, fabricated with a 0.15-mum CMOS process, were measured. These measurements show that the developed charge pump achieves the target regulation positive high voltage (+6.5 V) and negative high voltage (-6 V) at low power-supply voltage Vdd of 1.5 V while also achieving low power consumption.