On-chip power supply noise detector

In an integrated circuit, circuitry for detecting noise associated with a power supply line, comprising:

• a pair of sensors, the pair of sensors preconditioning a first signal and a second signal, the first signal being representative of a voltage of the power supply line on which noise is to be detected, the second signal being representative of a voltage of a reference power supply line, the preconditioning operation comprising shifting respective levels of the voltages such that the voltages are within an input voltage range of a pair of comparators;
• a pair of comparators respectively coupled to the pair of sensors, the pair of comparators comparing the preconditioned first signal and the preconditioned second signal, the comparing operation detecting when a difference exists between the voltage level of the preconditioned first signal and the voltage level of the preconditioned second signal;
• and
• a pair of inverter circuits respectively coupled to the pair of comparators, the pair of inverter circuits outputting an overshoot signal when the voltage level of the preconditioned first signal is greater than the voltage level of the preconditioned second signal and an undershoot signal when the voltage level of the preconditioned first signal is less than the voltage level of the preconditioned second signal.