Panasonic LN66F Infrared Emitter 950nm - Equivalent & Substitute Parts

Part Overview

The Panasonic LN66F is a through-hole infrared (IR) emitter operating at 950nm wavelength with a maximum forward current of 50mA and typical forward voltage of 1.35V. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing production and maintenance applications. The LN66F delivers 13mW/sr radiant intensity at 50mA with a 30° viewing angle, suitable for IR transmission applications requiring this specific wavelength and optical characteristics.

Substiute Parts

LN66F

Panasonic Electronic ComponentsIn Stock: 694LN66F Datasheet

Current PartRFQ

HSDL-4250

Lite-On Inc.In Stock: 1868HSDL-4250 Datasheet

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QED123

onsemiIn Stock: 4736QED123 Datasheet

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QED123A4R0

onsemiIn Stock: 7702QED123A4R0 Datasheet

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SIR-505STA47

Rohm SemiconductorIn Stock: 3069SIR-505STA47 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the LN66F is determined by the following critical parameters: wavelength (950nm), mounting type (through hole), forward current capability, forward voltage characteristics, viewing angle (30°), and operating temperature range. The substitute parts listed below maintain compatibility within these electrical and mechanical constraints.

Primary substitution criteria:

• Wavelength: 950nm (exact match required for IR transmission compatibility)
• Mounting Type: Through hole configuration
• Viewing Angle: 30° (matches optical beam characteristics)
• Operating Temperature Range: Minimum -25°C to 85°C coverage
• Forward Voltage: Nominal range 1.35V to 1.4V
• Current Rating: Minimum 50mA capability

Two substitute parts meet these criteria: the Rohm Semiconductor SIR-505STA47 (950nm, 30° viewing angle, -25°C to 85°C) and the Lite-On Inc. HSDL-4250 (870nm wavelength, alternative for applications tolerant of wavelength variation). The onsemi QED123 and QED123A4R0 operate at 880nm and 890nm respectively, representing wavelength alternatives for systems designed to accept near-infrared spectrum flexibility.

Parameter Comparison

Engineering Selection Recommendations

SIR-505STA47 (Rohm Semiconductor) provides the closest electrical and optical match to the LN66F, maintaining identical 950nm wavelength and 30° viewing angle with matching operating temperature range (-25°C to 85°C). This part is classified as "Not For New Designs" but remains suitable for legacy system maintenance and replacement applications. The SIR-505STA47 supports higher forward current (100mA vs. 50mA), providing design flexibility for existing circuits.

HSDL-4250 (Lite-On Inc.) is actively manufactured and ROHS3 compliant, offering extended operating temperature range (-40°C to 85°C). This part operates at 870nm wavelength with narrower 15° viewing angle and significantly higher radiant intensity (124mW/sr @ 100mA). Selection of this part requires system tolerance for wavelength deviation and optical beam narrowing.

QED123 and QED123A4R0 (onsemi) are actively produced with extended temperature range (-40°C to 100°C) and ROHS3 compliance. Both operate in the 880nm-890nm wavelength band with 16-18° viewing angles. These parts are suitable for applications designed to accept near-infrared spectrum alternatives and narrower beam angles.

For new designs, HSDL-4250 or onsemi QED series parts are recommended due to active product status and full compliance certifications. For legacy system replacement, SIR-505STA47 maintains closest compatibility with original LN66F specifications.

Frequently Asked Questions (FAQ)

Q: Can the SIR-505STA47 directly replace the LN66F in existing circuits?

A: The SIR-505STA47 maintains identical wavelength (950nm) and viewing angle (30°), with matching operating temperature range. Circuit compatibility depends on forward current design margins. The SIR-505STA47 supports 100mA maximum current versus the LN66F's 50mA, allowing operation at original current levels with additional headroom. Forward voltage is nearly identical (1.38V vs. 1.35V), requiring minimal circuit adjustment.

Q: What is the impact of wavelength differences when substituting with HSDL-4250 or QED series parts?

A: Wavelength selection determines IR transmission efficiency in specific applications. The LN66F operates at 950nm, while HSDL-4250 operates at 870nm and QED series at 880-890nm. Substitution with alternative wavelengths is valid only for systems designed to accept this spectrum range. Optical receiver sensitivity, atmospheric transmission, and application-specific filtering must be evaluated before wavelength substitution.

Q: Are all substitute parts through-hole mounted?

A: Yes, all listed substitute parts use through-hole mounting, maintaining mechanical compatibility with LN66F PCB layouts. Package designations (T 1 3/4 and Radial 5mm Dia) are standard through-hole IR emitter form factors with identical lead spacing and mounting hole compatibility.

Q: What compliance certifications apply to substitute parts?

A: HSDL-4250, QED123, and QED123A4R0 are ROHS3 compliant. The SIR-505STA47 is also ROHS3 compliant. All parts carry EAR99 export classification and HTSUS code 8541.41.0000. The onsemi QED series parts are REACH unaffected. Compliance verification should be confirmed against specific application and regional requirements.

Q: How do radiant intensity differences affect system performance?

A: Radiant intensity (measured in mW/sr) determines optical power output at specified current levels. The LN66F delivers 13mW/sr @ 50mA, while SIR-505STA47 delivers 5.6mW/sr @ 50mA (lower intensity), HSDL-4250 delivers 124mW/sr @ 100mA (higher intensity), and QED series deliver 50mW/sr @ 100mA. System receiver sensitivity and transmission distance requirements determine acceptable intensity ranges. Higher intensity parts may require circuit current limiting to prevent receiver saturation.