Holding Capacitor: Voltage Rating 16V to 100V DC

Q: What is the main function of a holding capacitor in a sample and hold circuit?

The holding capacitor temporarily stores an analog voltage signal sampled at a specific time and maintains it constant during the hold period, enabling accurate analog-to-digital conversion or signal processing without signal degradation.

Q: Why is low dielectric absorption important for a holding capacitor?

Low dielectric absorption minimizes voltage drift during the hold phase by reducing the capacitor's tendency to slowly release trapped charge, which ensures higher accuracy and stability in maintaining the sampled voltage.

Q: Can I use any capacitor as a holding capacitor in a sample and hold circuit?

No, standard capacitors may not be suitable due to issues like high dielectric absorption or leakage. Precision capacitors with materials like polypropylene or NP0 ceramic are preferred for their stability and low loss characteristics.

Component Specifications

Definition

A holding capacitor, also known as a storage capacitor or hold capacitor, is a critical component in sample and hold (S/H) circuits. It functions as a temporary analog memory element that captures and preserves an input voltage signal at a specific sampling instant. The capacitor stores electrical charge proportional to the sampled voltage and maintains this charge with minimal leakage during the hold period, enabling subsequent analog-to-digital conversion or signal processing without degradation. Key characteristics include low dielectric absorption, high insulation resistance, and stable capacitance over temperature and voltage variations.

Working Principle

The holding capacitor operates based on the fundamental principle of capacitive charge storage. During the sample phase, a switch (typically a MOSFET or analog switch) closes, connecting the capacitor to the input voltage signal. The capacitor charges or discharges to match the input voltage almost instantaneously. During the hold phase, the switch opens, isolating the capacitor from the input. The capacitor then retains the stored charge, maintaining a constant output voltage until the next sample cycle. The accuracy depends on factors like capacitor leakage current, dielectric absorption, and switch feedthrough.

Materials

Common materials include polypropylene film (for high stability and low dielectric absorption), polystyrene film (for precision applications), Teflon (PTFE) for ultra-low loss, or ceramic dielectrics like NP0/C0G (for temperature stability). Electrodes are typically made of metallized film or metal foil (aluminum, tin). Encapsulation materials include epoxy resin or plastic cases for protection.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Tolerance	±1% to ±10%
Voltage Rating	16V to 100V DC
Leakage Current	< 1 nA at rated voltage
Capacitance Range	100 pF to 10 nF (typical for S/H circuits)
Dielectric Absorption	< 0.01%
Temperature Coefficient	±30 ppm/°C or better
Equivalent Series Resistance (ESR)	< 0.1 Ω

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

Standards

ISO 9001, IEC 60384, MIL-PRF-123

Parent Products

This component is used in the following industrial products

Sample and Hold Circuit

An electronic circuit that samples an analog signal at a specific instant and holds that value constant for subsequent processing.

View Product Details

Sample-and-Hold Amplifier

An electronic circuit that captures and holds an analog voltage signal at a specific instant in time for subsequent processing.

View Product Details

Engineering Analysis

Risks & Mitigation

Voltage droop due to leakage current
Signal distortion from dielectric absorption
Temperature-induced capacitance drift
Switch feedthrough contamination

FMEA Triads

Trigger: High leakage current in capacitor
Failure: Voltage droop during hold period, leading to inaccurate signal retention
Mitigation: Use capacitors with specified low leakage current (e.g., < 1 nA) and ensure proper voltage derating.

Trigger: Poor dielectric absorption characteristics
Failure: Signal distortion and memory effect, causing errors in sampled voltage
Mitigation: Select capacitors with low dielectric absorption materials like polypropylene or polystyrene.

Trigger: Inadequate temperature stability
Failure: Capacitance variation with temperature, affecting hold accuracy
Mitigation: Use capacitors with stable temperature coefficients (e.g., NP0/C0G ceramics) and implement thermal management in circuit design.

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

Capacitance tolerance typically ±1% to ±5% for precision applications; voltage tolerance within 50% of rated voltage for reliability.

Test Method

Testing per IEC 60384 for capacitance, leakage current, and dielectric absorption; use of LCR meters for measurement, and temperature cycling tests for stability verification.

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.

Compare the published product scope and source details, then include your specifications and quantity in an enquiry.

Manufacturers of Holding Capacitor

Manufacturer profiles associated with Holding Capacitor.

Sourcing Holding Capacitor from China?

Tell us your specification and target quantity — we will match it against manufacturer records and come back with the factories that fit.

Request manufacturers We manufacture this

Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.

Compiled and source-reviewed by the CNFX editorial team. Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review

Related Components

Serial Interface

Serial interface for industrial data transmission between IoT gateways and legacy equipment using RS-232/422/485 protocols.

Marking Ink

Specialized ink for permanent identification on surface mount resistors during manufacturing.

Dielectric Layer

Insulating layer in surface mount capacitors that stores electrical energy through polarization.

Optical Window

Transparent optical component for light transmission in polycarbonate lens housings

Frequently Asked Questions

What is the main function of a holding capacitor in a sample and hold circuit?