Patent ID: 7880339

Claim:
Isolation circuitry for coupling between a power supply and processing circuitry in order to provide power to the processing circuitry whilst hiding a power consumption characteristic of that processing circuitry, the isolation circuitry comprising: a plurality of sub-circuits, each sub-circuit comprising: a capacitor; a first switch configured to provide a first connection between said capacitor and said power supply; a second switch configured to provide a second connection between said capacitor and an output to said processing circuitry; a third switch configured to provide a third connection across said capacitor to partially discharge said capacitor; and control circuitry configured to control said plurality of sub-circuits, such that within each sub-circuit said first switch, said second switch and said third switch are placed in an active state in a repeating sequence; each of said plurality of sub-circuits further comprising: a comparator configured to place said third switch in an open state when a predetermined non-zero voltage difference across said capacitor is reached during the active state of the third switch.