Patent ID: 7142041

Claim:
A circuit to shut down any charge pump having any number n (n: an integral number) of stages avoiding excessive voltages comprising: a control circuitry to control the shut-down of the charge pump having input and output, wherein the input comprises a shut-down signal, and the voltage levels of each of the n stages of the charge pump and the output comprises signals to shut switching means of each stage individually from the output backwards to the input according to the results of comparisons of the voltage levels of the nth stage with the voltage level of the (n−1)th stage and furthermore said signals to shut switching means to initiate the discharge of a capacitor of a related stage; n switching means for each stage of the charge pump to discharge the capacitor of the related stage, wherein one terminal of each of said switching means is connected via an own serial current limiting impedance to ground and the other terminal is connected to the voltage of the related stage and wherein the discharge of the related capacitor is controlled by said control circuitry; said n serial current limiting impedances, wherein each of them is connected between one of said n switching means for each stage to discharge the capacitor of the related stage; a control circuitry to control the normal operation of the charge pump until a shut-down signal is received and the control is taken over by said control circuitry to shut-down the charge pump; a supply voltage; n switching means for each stage to interconnect said n stages wherein said switching means can be activated as well by said control circuitry to control the normal operation as by the control circuitry to control the shut-down.