Various GND Bounce Parameters

Amplitude of a glitch or bounce dies with time. Depending on the direction of the switching edge, first pulse of the glitch can be either positive or negative. The following figure shows the parameters usually associated with SSN:
  • VOLP (peak) and VOLV (valley) for ground bounce
  • VOHP (peak) and VOHV (valley) for VCC bounce
Figure . Ground Bounce Parameters

The pulse width parameter or the settling time of the bounce is the time for which the signals stay over a given threshold criterion. As the waveform of a ground bounce pulse looks more like a sinusoid than a square wave, the pulse width depends on the point of measurement. This parameter is important because every input buffer has a limit on the smallest pulse that it can recognize with regard to width and amplitude. A smaller pulse is not recognized, even though the amplitude might be much higher, as shown in the following figure. For example, an input buffer with a minimum recognizable pulse width of 3 ns at 2V does not recognize a pulse that is 1 ns wide, even if its amplitude is 2.5V.

Therefore, with regard to noise, pulse width, and voltage amplitude of the glitch must be minimized so that it is not interpreted as a logic pulse by the input buffer of the receiving device.

Figure . Voltage vs. Pulse Width Plot of an Input Buffer