3-Terminal Capacitor

"A", "B/C", "D", "E", "F", "G", "I/L",
"M/N/O", "P", "Q/R", "S", "T", "V/Z"

3-Terminal Capacitor: A capacitor having a third terminal which connects to ground. A three terminal capacitor may be a through-hole with 3 leads or surface mount with 3 pads. Primarily 3-Terminal Capacitors are multilayer ceramic chip capacitors which are used in EMC / RFI Suppression conditions.

The structure of a 3-Terminal Capacitor appears almost as a Feedthrough Capacitor which is shown to the right.

Inductor T-Filter, Capacitor Shunt

A feed-through capacitor can be considered to be a kind of a 3-terminal capacitor. The difference between a Feedthrough Capacitor and a 3-Terminal Capacitor is the additional inductance in the ground lead [not shown]. However the two inductors that are shown represent lead inductance and not true inductors.

Surface Mount 3-Terminal Capacitor

3-Terminal Capacitors have a smaller Equivalent Series Inductance [ESL] because the distance from a positive electrode to a ground (GND) electrode is shorter and the cross-sectional area of a rectangular solid is larger. In order to make ESL smaller, capacitors have to be shorter in length and longer in width. This principle ultimately leads to a three-terminal shape, in which the power line is incorporated in the component, and the distance from the power line as a positive electrode to the GND electrode is shortest.

Pad Location of a 3-Terminal SMD Capacitor
3-Terminal SMD Capacitor

Through-hole 3-Terminal Capacitor

There are a number of possible capacitor styles that could be 3 terminal devices, these are just a few examples. It appears that in general 3-Terminal Capacitors use a ceramic dielectric [from what I've found].

Editor note; Image is for illustrative purposes only. Any number of package sizes could be used for each of the styles shown as examples.

Through hole 3 terminal capacitor
3-Lead Capacitor

[Manufacturers of Ceramic Capacitors]

PC motherboard

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