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

SAL: Solid Aluminum. A reference to an aluminum electrolytic capacitor in a radial lead package [in a molded or non-metal package].

Screw Terminal: A capacitor that uses terminals to secure wire leads to a capacitor via bolting a lug onto a capacitor. In many cases larger Aluminum Electrolytic Capacitors may use screw terminals for lead attachment. Screw Terminal capacitors are mounted by being clamped to a surface, because this type of construction does not use leads for either surface mounting or through-hole mounting. The terminals are not used to secure or attach the capacitor to a PCB, but only as connection points.


Graphic of a Capacitor with Screw Terminals per MIL-PRF-39018
Screw Terminal Capacitor

Self Inductance: The self inductance or equivalent series inductance results from the terminal configuration and the internal design of the capacitor.

Shelf Life: The capacitance, ESR and impedance of a capacitor will not change significantly after extended storage periods. However, the leakage current will very slowly increase. Also refer to the Capacitor Aging definition.

Silver Mica: A mica capacitor that uses silver deposited on the mica sheets instead of metal foil. See Mica Capacitor

SLC: Single Layer Ceramic.

SLCC: Single Layer Ceramic Chip.

SMD: Surface Mount Device.
A SMD capacitor may be a leaded or non-leaded component [shown]. However most surface mount components are non-leaded, using terminals instead.
Common chip Capacitor sizes page [non-leaded].

General shape of chip capacitors
SMD Capacitors

SMT: Surface Mount Technology. Common chip styles include Cylindrical Can, Horizontal Mount, and Flat Chip. Chip capacitor Physical Size page.

Snap-in Capacitor
Snap-In Electrolytic Capacitor

Snap-in: A mounting style used by through-hole components. Snap-in solder pins are used to hold the component in place on a PC-board [PCB].

Snubber Capacitor: A capacitor incorporated into a rapidly switched LC circuit to reduce emi by lowering the circuit resonant frequency and characteristic impedance. This example Snubber cap encapsulates both a 0.1uF capacitor and a 120 ohm resistor.
RC Snubber Capacitor
Snubber Capacitor

Speed-Up Capacitor: A capacitor placed across the Base resistor in parallel. Initially the capacitor appears as a short, by-passing the Base resistor decreasing switching time [Speeding-Up], so the transistor turns on faster. Refer to the speed-up capacitor circuit diagram in the right side-bar [0.01uF capacitor].

Stability: The ability of a part to resist changes of characteristic values and coefficients.
a. Surge voltage (or current). Transient variation in the voltage or current at a point in the circuit; a voltage or current of large magnitude and short duration caused by a discontinuity in the circuit.
b. Temperature coefficient (TC). Change in capacitance of a capacitor per degree change in temperature. It may be positive, negative, or zero and is usually expressed in parts per million per degree Celsius (ppm/qC). Capacitor Value vs Temperature Chart.

Stabilizing Capacitor: A capacitor used to prevent oscillations and stabilize a circuit. Also called a Stabilization Capacitor which might be placed across a power terminal, feed-back resistor, input resistor, or as required for circuit stability and prevent oscillations, for example.

Stitching Capacitor: A capacitor placed between two adjacent planes that were being used as a reference but have no connection point. The capacitor AC couples the planes forming a continuous reference plane [while blocking DC]. One capacitor should be used for each signal that passes between the two planes, or if space permits use one capacitor on either side of the signal as it passes between the planes. A stitching capacitor reduces the current loop area of the return path and the discontinuity by providing a a high frequency path from one plane to the other.

A stitching capacitor is normally required when a trace is using a power plane(s) as a reference. Traces should be routed around any discontinuities in ground planes so that their return currents are able to follow the signal trace with out interruption.
Good design practice dictates that that there should be no slots in ground planes.
Definition of a Split-Plane [showing a stitching capacitor].

Storage Shelf Life: See Shelf Life.
Also refer to MIL-HDBK-1131; Storage Shelf Life and Reforming Procedures for Aluminum Electrolytic Fixed Capacitors.

Substitution: A capacitor with a tighter tolerance can replace a lesser tolerance capacitor. A higher working voltage capacitor may replace a lower working part. A tighter 1% capacitor may replace a 2 % temperature capacitor. Normally a devices size may not be substituted for another part, as there are layout pad placement or height consideration to account for.

Super-capacitor: A capacitor having a high energy density, a high capacitance in a small package. A Supper-Capacitor may also be called an ultra-capacitor.

Surge Voltage: A momentary increase in applied voltage over the intended circuit design or operating voltage.

Switch-Mode Capacitor: Ceramic capacitors designed to be used with Switch-Mode Power Supplies [SMPS]. A multi-lead capacitor. Note the large number of leads or terminals, for a single capacitor [see circuit diagram to right]. The number of component terminals help to lower ESR of the capacitor. Switch mode capacitors are available in a number of standard voltages and tolerances. However normally the actual capacitor values are some what limited. The three main terminal styles available are leaded through-hole or surface mount [pictured]; as J-lead and L-lead. MIL-PRF-49470: Fixed Ceramic Dielectric Capacitor; Switch Mode Power Supply (General Purpose and Temperature Stable).

Synchro Capacitor: A unit containing three delta-connected capacitors. The synchro capacitor is used in synchro systems to increase the systems accuracy by cancelling or reducing the phase shift introduced by synchro inductance.

 
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