INDUSTRY COMPONENT

Coupling Capacitor

A coupling capacitor is an electronic component that blocks DC voltage while allowing AC signals to pass between circuits in voltage amplification stages.

Component Specifications

Definition
A coupling capacitor is a passive electronic component specifically designed to transfer alternating current (AC) signals from one circuit to another while blocking direct current (DC) voltage. In voltage amplification stages, it isolates the DC bias of different amplifier stages while enabling AC signal transmission, preventing DC offset from affecting subsequent stages and ensuring proper amplifier operation.
Working Principle
The coupling capacitor operates based on capacitive reactance, which varies with signal frequency. At DC (0 Hz), the capacitor presents infinite impedance, effectively blocking DC voltage. For AC signals, the capacitor's impedance decreases with increasing frequency, allowing signals to pass through. This frequency-dependent behavior enables selective coupling of AC signals while maintaining DC isolation between circuit stages.
Materials
Dielectric materials: Ceramic (Class 1: NP0/C0G, Class 2: X7R, Y5V), Polyester film (PET), Polypropylene film (PP), Polystyrene film (PS), Tantalum pentoxide (for tantalum capacitors). Electrode materials: Silver, Nickel, Copper, Aluminum. Encapsulation: Epoxy resin, Ceramic casing.
Technical Parameters
ParameterTypical rangeNotes & selection driver
Tolerance±1% to ±20%
Voltage Rating16V to 1000V DC
Leakage Current<0.01CV μA or 0.5μA (whichever greater)
Capacitance Range1pF to 100μF
Dielectric Absorption<0.1% to 1%
Temperature Coefficient-55°C to +125°C
Equivalent Series Resistance (ESR)10mΩ to 100Ω

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards
IEC 60384, MIL-PRF-123, EIA RS-198, JIS C 5102

Parent Products

This component is used in the following industrial products

Engineering Analysis

Risks & Mitigation
  • DC leakage causing bias shift
  • Dielectric breakdown at overvoltage
  • Capacitance drift with temperature
  • Electrolytic drying in humid environments
  • Microphonic effects in ceramic types
FMEA Triads
Trigger: Voltage exceeding rated maximum
Failure: Dielectric breakdown leading to short circuit
Mitigation: Use capacitors with 50-100% voltage margin, implement overvoltage protection circuits
Trigger: High temperature operation
Failure: Capacitance value drift and reduced lifespan
Mitigation: Select capacitors with appropriate temperature rating, ensure proper ventilation, use temperature-stable dielectrics like NP0/C0G
Trigger: Mechanical stress on leads
Failure: Internal connection breakage creating open circuit
Mitigation: Proper PCB mounting with stress relief, avoid bending leads close to body, use strain relief in cable applications

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance
Capacitance tolerance typically ±5% to ±20% depending on application, voltage tolerance must exceed circuit maximum by 50-100%
Test Method
Capacitance measured at 1kHz using LCR meter, leakage current tested at rated voltage after 2-minute soak, ESR measured at 100kHz, dielectric withstand tested at 2x rated voltage for 60 seconds

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation
Request current drawings, revision history, and a signed specification sheet.
Manufacturing capability
Verify equipment lists, process limits, capacity, and representative production evidence.
Inspection readiness
Confirm test methods, calibrated equipment, sampling plans, and traceable reports.
Supplier transparency
Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Coupling Capacitor

1 company lists this product among what they make. Company figures are quoted from each company's own website; every card states where the relationship came from.

Shangdian
Shanghai, CN
Also makes: Capacitor Bank
Listed on the company's own website · profile compiled by CNFX from public sources
Listed there as: “Coupling capacitor”
View source page ↗ sdcapacitor.com · checked 2026-09-10

Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

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Frequently Asked Questions

What happens if a coupling capacitor fails in an amplifier circuit?

Capacitor failure typically causes loss of signal transmission, resulting in no output or distorted audio. Common failure modes include open circuit (no signal passes), short circuit (DC leakage affects bias), or value drift (frequency response changes).

How do I select the right coupling capacitor value?

Select capacitance based on the lowest frequency to be coupled. Use formula C = 1/(2πfR) where f is cutoff frequency and R is input impedance. Typical values range from 0.1μF to 10μF for audio applications. Consider voltage rating, tolerance, and temperature stability.

Can coupling capacitors affect sound quality in audio amplifiers?

Yes, capacitor characteristics influence audio performance. Dielectric absorption can cause signal memory effects, ESR affects high-frequency response, and nonlinearities in some dielectrics may introduce distortion. Film capacitors generally offer better audio performance than ceramic types.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification
This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

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