What capacitor type should be chosen for AC coupling?
A. Most CML products have audio signal paths that require AC coupling to add a high pass filter function to the audio path or to prevent DC offsets from affecting bias conditions around the device input. Designers naturally target a small package and low cost so it is likely a multi-layer ceramic capacitor will be chosen for the coupling. Ceramic is a material that demonstrates some interesting characteristics when subjected to variations in external conditions. Generally, ceramic capacitors have very poor temperature stability, a very wide manufacturing tolerance and a high drift value with age. Resonant points occur in the frequency characteristic but these are unlikely to be a problem in unless AC coupling high-speed clocks or signals with fast edges. The material also has some lesser-known characteristics such as the variation in value with ambient moisture and the piezo effect that causes the ceramic to physically distort with applied voltage. The latter effect results in a change
Related Questions
- How much is the inrush current and the stall current of the AC Induction and AC Reversible motors, and what type of fuse or breaker should I use to protect motor?
- Why is silicon nitride chosen for the tip material for the cantilevers for AC mode AFM?
- What capacitor type should be chosen for AC coupling?
