CHARGE PUMPING CIRCUIT FOR A SUBSTRATE VOLTAGE GENERATOR

摘要

In the pumping circuit a charge is pumped from the substrate of a VLSI chip through a PN diode (D3) to a node (B) in response to periodic input signals coupled through a purnping FET capacitor (T1) to said node (B), said pumped charge then passing through a current sinking FET transistor (T2) to a reference potential, thereby providing a desired substrate voltage to said substrate.
The pumping FET capacitor (T1) has a high capacitance by means of a triple plate structure. In addition a space saving technique of providing a dual use for the source diffusion of the current sinking device in the circuit is applied so as to also serve as the guard ring around the charge pumping circuit of the substrate voltage generator.