INDUSTRY COMPONENT

Photodetector (for optocoupler)

Semiconductor device that converts optical signals into electrical signals within optocouplers for electrical isolation.

Component Specifications

Definition
A photodetector in optocoupler applications is a semiconductor-based component, typically a photodiode or phototransistor, that detects incoming light from an LED emitter and converts it into proportional electrical current. It serves as the receiver element in optocoupler isolation circuits, enabling signal transmission while maintaining galvanic isolation between input and output circuits.
Working Principle
Operates on the photoelectric effect where incident photons from the optocoupler's LED emitter generate electron-hole pairs in the semiconductor material. This creates a photocurrent proportional to light intensity, which is then amplified and processed to reproduce the input signal on the isolated output side.
Materials
Silicon (Si) or Gallium Arsenide (GaAs) semiconductor materials; typically PIN photodiodes or NPN phototransistors with anti-reflective coatings; hermetic ceramic or plastic packaging with optical windows.
Technical Parameters
ParameterTypical rangeNotes & selection driver
Dark Current<10 nA
Responsivity0.5-0.8 A/W
Rise/Fall Time2-10 μs
Isolation Voltage2500-5000 Vrms
Spectral Response800-950 nm (infrared)
Operating Temperature-40°C to +100°C
Current Transfer Ratio20-600%

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 60747-5-5, JEDEC JESD22

Parent Products

This component is used in the following industrial products

Engineering Analysis

Risks & Mitigation
  • Degradation of CTR over time
  • Thermal runaway in high-current applications
  • Optical window contamination reducing sensitivity
  • ESD damage during handling
FMEA Triads
Trigger: LED output degradation over time
Failure: Decreased Current Transfer Ratio (CTR)
Mitigation: Implement burn-in testing, use conservative CTR derating (50% of initial value), and monitor with periodic functional testing.
Trigger: Moisture ingress in non-hermetic packages
Failure: Increased dark current and potential short circuits
Mitigation: Use conformal coating, hermetic packaging for harsh environments, and proper storage with desiccants.

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance
CTR variation ±20% typical, isolation voltage tested at 125% of rated value for 1 minute
Test Method
IEC 60747-5-5 for optoelectronic isolation, UL 1577 for voltage withstand, and AEC-Q101 for automotive qualification

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 Photodetector (for optocoupler)

Manufacturer profiles associated with Photodetector (for optocoupler).

Sourcing Photodetector (for optocoupler) 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

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

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 difference between photodiode and phototransistor detectors in optocouplers?

Photodiodes offer faster response times but require external amplification, while phototransistors provide higher sensitivity and built-in gain but slower switching speeds. Selection depends on application speed and sensitivity requirements.

How does temperature affect photodetector performance in optocouplers?

Temperature variations affect dark current (doubles every 10°C rise), responsivity (decreases with temperature), and CTR (typically decreases 0.5-1.0%/°C). Proper thermal design and derating are essential for reliable operation.

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.

Request Manufacturing Insight for Photodetector (for optocoupler)

Thank you. Your request has been sent. We'll respond within 1–3 business days.
Sorry, we couldn't send your message. Please try again, or email us at contact@cnfx.com.
XOR Gate
Get QuotesChat