Feedthrough Capacitors

A capacitor feed-through, also known as a capacitor feedthrough, is a specialized type of electrical component that combines the functions of a capacitor and a feedthrough. It is designed to pass electrical signals through a barrier, such as the wall of an enclosure, while maintaining electrical isolation between the two sides of the barrier. Here's a concise introduction to the capacitor feed-through:

Definition:
A capacitor feed-through is an electrical component that allows a signal to pass through an insulating barrier, typically a metal or plastic wall, while also providing a capacitive coupling. It is often used in high-frequency applications where signal integrity and isolation are crucial.

Function:
The primary function of a capacitor feed-through is to transmit electrical signals across a barrier without creating a direct electrical path. This is achieved by using a capacitor to couple the signal across the barrier. The capacitor's dielectric material prevents direct current flow but allows alternating current (AC) signals to pass through. This is particularly useful in applications where electromagnetic interference (EMI) needs to be minimized, and signal integrity must be maintained.

Applications:
Capacitor feed-throughs are used in various applications, including:
1. Shielded enclosures where signals need to be transmitted in or out while maintaining the integrity of the shield.
2. Medical equipment where isolation is required for safety reasons.
3. High-frequency communication systems where signal integrity is critical.
4. Test and measurement equipment where signals need to be transmitted across a grounded barrier.

Selection Criteria:
When selecting a capacitor feed-through, the following criteria should be considered:
1. Capacitance Value: The capacitance should be appropriate for the frequency range of the signal being transmitted.
2. Voltage Rating: The feed-through should be able to handle the voltage levels of the application without breaking down.
3. Current Rating: It should be able to handle the current levels without overheating or failing.
4. Material: The dielectric material should be chosen based on the application's requirements for signal transmission and isolation.
5. Physical Dimensions: The size and shape should fit within the design constraints of the equipment.
6. Environmental Resistance: It should be able to withstand the environmental conditions of the application, such as temperature, humidity, and chemical exposure.

In summary, capacitor feed-throughs are essential components in many electronic systems where signal transmission across a barrier is required while maintaining electrical isolation. Their selection should be based on a careful consideration of the application's specific needs.
Please refer to the product rule book for details.