What is the Use of a Decoupling Capacitor?
- System noise has become a critical issue for both analog and digital devices.
- The requirement for speedy interfaces and lower power consumption has resulted in devices being sensitive to disturbances from power and signal lines.
- A decoupling capacitor or bypass capacitor in a circuit provides high transient currents to an IC and reduces power ripples.
- Such capacitors are placed close to the power pins of an IC.
- Analog circuits such as audio amplifiers produce a hum or a crackling noise during operation, while digital circuits such as micro-controllers exhibit erratic and unpredictable behavior.
- It happens because the input voltage is not stable.
- Any device will perform accurately if variations such as glitches, voltage spikes, and AC components remain within the tolerance.
- A good PCB design must ensure smooth input voltage by addressing intra-system power noise with adequately placed decoupling and bypass capacitors.