Backup capacitor
As a back-up capacitor , the insert is a capacitor for stabilizing the supply voltage in high-frequency and complex digital circuits , respectively. In function it is similar to a smoothing capacitor . Here, for each IC or circuit section, one or more capacitors are connected in parallel to the supply voltage, which act as a voltage or energy source in moments of high current or power demand. Due to their low impedance at high frequencies, they reduce the impedance of the higher-level power supply or its supply line and prevent the power supply of subcircuits from influencing each other. On the output signal lines, they reduce both " overshoots " and "undershoots" of the signal level and thus the possibility of interference in signal processing. Conversely, capacitors can absorb disruptive, temporary overvoltages in electronic circuits and thus reduce their spread and harmful effects.
literature
- Howard W. Johnson, Martin Graham: High-Speed Digital Design . Prentice hall PTR, 1993, ISBN 0-13-395724-1 , Chapter 8: Power Systems .