PT42-21B/TR8 Everlight Phototransistor (Other) In Stock
The Everlight PT42-21B/TR8 is a RoHS-compliant miniature surface-mount infrared phototransistor in a 2-pin SMD package with a 30 V collector-emitter breakdown voltage and 3 mA nominal light current. It offers low dark current of 100 nA for high-contrast optical sensing applications. Available from stock worldwide with competitive pricing.
- Manufacturer
- Everlight
- Package
- Other
- Pin Count
- 2
- Lifecycle
- ACTIVE
- Datasheet
- PT42-21B/TR8 Datasheet PDF
- Category
- Phototransistor
- Price
- From $0.0370(MOQ 1000)
- Temp Range
- -25.0°C to 85.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
What are the key features of PT42-21B/TR8?
- Infrared-sensitive phototransistor with 3 mA nominal light current and 100 nA maximum dark current for high-sensitivity optical detection
- 30 V collector-emitter breakdown voltage and 20 mA maximum on-state current support a wide range of signal switching applications
- Compact 2-pin SMD package with RoHS and Pb-free compliance enables automated PCB assembly in space-constrained sensor designs
What is PT42-21B/TR8 used for?
The PT42-21B/TR8 is used in proximity sensors, optical encoders, and line-detection modules where a miniature SMD infrared phototransistor is required. Its low dark current of 100 nA and 3 mA light current enable reliable discrimination between ambient and IR-illuminated states in industrial counting and position feedback systems. Engineers also use this phototransistor in consumer electronics for touchless button sensing and paper-feed detection in printers and copiers.
What are the specifications of PT42-21B/TR8?
| Pbfree Code | Yes |
| YTEOL | 6.99 |
| Coll-Emtr Bkdn Voltage-Min | 30V |
| Configuration | SINGLE |
| Dark Current-Max | 100nA |
| Infrared Range | YES |
| Light Current-Nom | 3mA |
| Mounting Feature | SURFACE MOUNT |
| Number of Functions | 1 |
| On-State Current-Max | 0.02A |
| Optoelectronic Device Type | PHOTO TRANSISTOR |
| Peak Wavelength | 940nm |
| Power Dissipation-Max | 0.075W |
| Shape | ROUND |
| Size | 1.8mm |
| Surface Mount | YES |
| Package | Other |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| ECCN | EAR99 |
| HTS Code | 8541.40.70.80 |
Where can I find the PT42-21B/TR8 datasheet?
PT42-21B/TR8 Datasheet DownloadOfficial datasheet from Everlight
What are equivalent replacements for PT42-21B/TR8?
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
What are the key electrical parameters of the Everlight PT42-21B/TR8 phototransistor?
The PT42-21B/TR8 has a 30 V minimum collector-emitter breakdown voltage, a nominal light current of 3 mA, and a maximum dark current of 100 nA. Maximum on-state current is 20 mA. These parameters make it a sensitive and reliable infrared detector for optical switches, proximity detectors, and encoder feedback systems operating at typical logic supply voltages.
How does the SMD package of PT42-21B/TR8 benefit automated optical sensor assembly?
The 2-pin SMD form factor of PT42-21B/TR8 is compatible with pick-and-place equipment and reflow soldering, enabling high-volume automated assembly at lower cost than through-hole alternatives. The miniature plastic body reduces PCB footprint to just a few square millimeters, allowing multiple phototransistors to be placed in proximity for array-based optical detection tasks such as barcode scanning and position encoding.
In proximity detection designs, how does the PT42-21B/TR8 compare to phototransistors with higher dark current?
With a maximum dark current of only 100 nA, the PT42-21B/TR8 provides a much larger signal-to-noise ratio between its 3 mA light current and dark state compared to phototransistors rated at 500 nA or higher. This 30:1 or greater contrast ratio makes it easier to set reliable detection thresholds in proximity and object-detection circuits, especially in industrial environments with high ambient IR noise at 30 V operating conditions.
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Why Buy from FindMyChip
About Everlight
Everlight is a leading electronic component manufacturer. FindMyChip sources Everlight ICs directly from authorized China distributors, offering competitive pricing and reliable stock.
| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 1000+ | $0.0500 | $50.00 |
| 3000+ | $0.0450 | $135.00 |
| 27000+ | $0.0370 | $999.00 |
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