Circuit for clamping current in a charge pump

摘要

A circuit for clamping current in a charge pump is disclosed. The charge pump includes switching circuitry having a number of switching circuitry transistors. Each of first and second pairs of transistors in the circuit can provide an additional path for current from its associated one of the switching circuitry transistors during off-switching of that transistor so that a spike in current from the switching circuitry transistor is only partially transmitted through a path extending between the switching circuitry transistor and a capacitor of the charge pump.

主权项

1. A charge pump comprising:
a plurality of transistors; at least one capacitor; a first path configured to communicate current with the at least one capacitor, wherein a first transistor of the plurality of transistors is located on the first path and generates a first temporary parasitic spike in current when the first transistor switches off in response to a control signal changing from a first value to a second value; and a current clamping circuit configured to:
open an additional path for current from the first transistor when the control signal changes from the first value to the second value such that the first temporary parasitic spike is only partially communicated through the first path; andclose the additional path after the additional path has been open for a period of time and the first temporary parasitic spike has dissipated.