Patent ID: 7301320

Claim:
An on-chip detector for detecting noise on the chip's power supply bus comprising in combination: a first current source on said chip, said first current source connected to the power supply bus and responding quickly to a change in supply voltage on said bus; said first current source includes a first FET transistor having a source, a drain, and a gate connected to said drain, a first resistor connecting said bus to said first FET transistor's drain, and a capacitor connecting said gate to said source, and said second current source includes a second FET transistor having a source, a drain, and a gate connected to said drain, a second resistor connecting said bus to said second FET transistor's drain; a second current source on said chip, said second current source connected to said power supply bus and responding more slowly than said first current source to said change in said supply voltage; and means responsive to a difference in current flow between said first current source and said second current source to generate an output signal indicating the presence of a noise signal on said bus.