Multistage regulator for charge-pump boosted voltage applications

摘要

A multistage circuit for regulating the charge voltage or the discharge current of a capacitance (CLOAD) of an integrated device at a certain charge-pump generated boosted voltage is safely implemented without obliging to integrate high voltage transistor structures of type of conductivity of the same sign of the boosted voltage (high-side transistors).Another fulfilled objective is to provide a multilevel nonvolatile flash memory device comprising a boosted voltage regulator that can be entirely fabricated with a low cost nonvolatile flash memory fabrication process.Basically, the multistage circuit for regulating the charge voltage or the discharge current of a capacitance in an integrated device, comprising at least a first stage and an output stage in cascade to the first stage and coupled to the capacitance, has the first stage supplied at an unboosted power supply voltage (VDD) of the integrated device and the output stage supplied at an unregulated charge-pump generated boosted voltage (VPUMP) and is composed of a transistor (MNOUT) of type of conductivity opposite to the sign of the boosted voltage and of the power supply voltage.The drain of the output stage transistor is coupled to the boosted voltage either through a resistive pull-up (RPULL-UP) or a voltage limiter.