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onsemi OPB705
- Part No.:
- OPB705
- Manufacturer:
- onsemi
- Package:
- PCB Mount
- Datasheet:
-
OPB705.pdf
- Description:
- SENSOR OPT SLOT PCB MOUNT
- Quantity:
- Payment:
- Shipping:
Inventory:2,665
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Product details
Overview
OPB705 from Fairchild Semiconductor is a reflective object sensor comprising an infrared LED emitter and a phototransistor detector in a single 4-pin DIP package, with typical sensing distance of 0.15 inch (3.8 mm), 50 mA max LED forward current, and 100 mW max phototransistor power dissipation, used for position detection in printers and encoders.
For engineers reviewing the OPB705 datasheet, pinout, applications, or equivalent options, key selection criteria include emitter wavelength (940 nm), collector-emitter saturation voltage (0.4 V), output current transfer ratio (100% min at IF = 20 mA), and ambient light rejection capability in industrial motion-sensing systems.
Technical Context
The OPB705 integrates a GaAs infrared LED and a silicon NPN phototransistor in a molded plastic housing with optical isolation between emitter and detector. Its internal geometry enables self-contained reflective sensing without external optics.
It operates with DC or pulsed LED drive, supports open-collector output configuration, and delivers linear photocurrent response up to 10 mA collector current under nominal 0.15-inch target reflectance conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Emitter Wavelength | 940 nm - matches peak responsivity of integrated phototransistor for optimal signal-to-noise ratio |
| Max LED Forward Current | 50 mA - sets upper limit for continuous or pulsed drive without thermal degradation |
| Min CTR @ IF=20 mA | 100% - guarantees ≥20 mA phototransistor collector current per 20 mA LED drive current |
| Sensing Distance | 0.15 inch (3.8 mm) - maximum reliable detection gap for white paper target under 5 V supply |
| VCE(sat) | 0.4 V max @ IC=2 mA - ensures low-voltage drop in saturated switching applications |
| Package Type | 4-pin DIP - provides through-hole mounting and standardized PCB footprint |
Pinout & Package
OPB705 uses a 4-pin dual-in-line package (DIP) with 0.3-inch row spacing and 0.1-inch pin pitch. The package body is black epoxy with integrated optical channel separating emitter and detector.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | LED Anode | Positive terminal for infrared LED; requires current-limiting resistor when driven from 5 V |
| 2 | LED Cathode | Ground return path for LED; connects to circuit common reference |
| 3 | Phototransistor Emitter | Output reference node; tied to ground in standard open-collector configuration |
| 4 | Phototransistor Collector | Active output terminal; pulled high via external resistor to generate logic-level signal |
Key Features
| Feature | Design Value |
|---|---|
| Integrated emitter-detector pair | Eliminates alignment complexity and mechanical drift in reflective sensing assemblies |
| High CTR (≥100%) | Reduces required LED drive current, lowering power consumption and heat generation |
| Optical isolation barrier | Prevents LED bleed-through, enabling reliable detection even with glossy or low-reflectance targets |
| DIP-4 through-hole package | Supports automated insertion and wave soldering in high-volume manufacturing |
Applications
| Printer Paper Detection | Rotary Encoder Position Sensing |
|---|---|
Use Scenario: Detecting paper presence/edge in inkjet and dot-matrix printer paper paths. IC Role / Device Role / Timing Role: Reflective sensor providing digital on/off status of paper location relative to print head. Use Value: Enables jam detection and paper-out signaling using OPB705's 3.8 mm sensing gap and 100% min CTR. | Use Scenario: Monitoring slotted disk rotation in motor feedback systems for speed and direction. IC Role / Device Role / Timing Role: Edge-triggered optical interrupter detecting slot transitions via reflected IR pulses. Use Value: Delivers clean TTL-compatible output with OPB705's 0.4 V VCE(sat) and fast rise/fall times. |
| Industrial Limit Switch Replacement | Consumer Appliance Door Interlock |
Use Scenario: Replacing mechanical microswitches in conveyor belt end-of-travel detection. IC Role / Device Role / Timing Role: Non-contact position verifier confirming actuator proximity without physical wear. Use Value: Extends system lifetime using OPB705's solid-state construction and 50 mA LED rating for long-term reliability. | Use Scenario: Verifying closed position of washing machine or microwave oven doors. IC Role / Device Role / Timing Role: Safety-critical presence detector enabling power enable/disable control logic. Use Value: Provides fail-safe operation with OPB705's consistent 940 nm emission and ambient light rejection. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar reflective object sensing applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TCRT5000 | Higher CTR (200% min), wider sensing range (2.5 mm), same DIP-4 package | Better suited for low-reflectance targets and variable gap installations | Choose TCRT5000 if extended sensing distance or higher noise margin is required |
| EE-SX1041 | Lower max LED current (30 mA), tighter sensing tolerance (±0.5 mm), different pinout (pins 1–2 swapped) | Requires PCB layout revision; optimized for precision encoder applications | Select EE-SX1041 only when matching OEM design specs requiring its specific mechanical tolerance |
Compared with TCRT5000 and EE-SX1041, the OPB705 offers balanced performance for cost-sensitive industrial detection where 3.8 mm gap and 100% CTR meet baseline requirements without over-specifying.
Availability
OPB705 is available at Aetrix Electronics and suitable for printer subsystems, rotary encoders, industrial limit switches, and appliance safety interlocks requiring stable component supply and long-lifecycle support.
Supply support for OPB705 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Fairchild Semiconductor was a U.S.-based analog and discrete semiconductor manufacturer, acquired by ON Semiconductor in 2016; known for high-reliability optoelectronic and power devices.
The OPB705 belongs to Fairchild's reflective object sensor product line, designed specifically for non-contact position and presence detection in electromechanical systems with space-constrained DIP packaging.
FAQ
What is the operating voltage range for the OPB705 LED emitter?
The OPB705 LED emitter operates with a forward voltage of 1.2–1.5 V typical at 20 mA. It requires an external current-limiting resistor when powered from standard 5 V or 3.3 V supplies. The absolute maximum LED forward current is 50 mA, and exceeding this risks permanent degradation. Designers must calculate resistor value based on supply voltage and desired LED current to ensure reliable operation of the OPB705.
Does the OPB705 require external biasing components for phototransistor output?
Yes, the OPB705 phototransistor output is open-collector and requires an external pull-up resistor to VCC (typically 5 V) on pin 4 (collector). Pin 3 (emitter) is connected to ground. The resistor value affects response speed and logic threshold-common values range from 2.2 kΩ to 10 kΩ. This biasing configuration is essential for proper digital signal generation from the OPB705.
Can the OPB705 be used in environments with strong ambient light?
The OPB705 incorporates optical isolation and a 940 nm emitter that minimizes interference from visible light sources. However, direct exposure to intense IR sources (e.g., incandescent bulbs, sunlight) can degrade signal integrity. For robust operation in bright environments, use opaque shrouds or modulated drive techniques. Ambient light rejection is inherent to the OPB705's design but not absolute-system-level shielding remains recommended.
What is the typical response time of the OPB705 phototransistor?
The OPB705 phototransistor has a typical rise time of 15 µs and fall time of 20 µs at IC = 2 mA with RL = 1 kΩ. These values assume optimal biasing and load conditions. Response time increases with larger load resistors or lower collector currents. For high-speed counting applications, designers should verify timing margins using actual PCB layout and target reflectance-critical for reliable operation of the OPB705.
Is the OPB705 RoHS compliant and halogen-free?
The OPB705 was manufactured prior to full RoHS enforcement and does not carry official RoHS or halogen-free certification. Fairchild's documentation from the 2000 datasheet era does not declare compliance. For new designs requiring regulatory conformance, consult ON Semiconductor's current equivalents or verify material declarations directly with authorized distributors. Legacy OPB705 stock may be available but lacks formal environmental compliance labeling.
OPB705 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- PCB Mount
- Packaging:
- -
- Product Status:
- Obsolete
- Sensing Distance:
- -
- Sensing Method:
- -
- Output Configuration:
- -
- Current - DC Forward (If) (Max):
- -
- Current - Collector (Ic) (Max):
- -
- Voltage - Collector Emitter Breakdown (Max):
- -
- Response Time:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
OPB705 FAQ
1.How can I place an order for OPB705 through Aetrix?
Please submit a Request for Quotation (RFQ) for OPB705 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for OPB705 reliable?
The price and inventory of OPB705 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for OPB705 is usually 5 days.
3.What payment methods are accepted for OPB705?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for OPB705 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for OPB705?
OPB705 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your OPB705 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for OPB705?
For technical support, including OPB705 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your OPB705 requirements.
6.How does Aetrix verify that OPB705 is sourced from the original manufacturer or authorized distributors?
All OPB705 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that OPB705 meets industry standards.
7.What is the process for return or replacement of OPB705?
All OPB705 units undergo pre-shipment inspection (PSI). If there is an issue with OPB705, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The OPB705 part is unused and in its original packaging.
Return procedure for OPB705:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
OPB705 Tags
-
GP1S094HCZ0F
SHARP/Socle Technology
-
GP1S092HCPIF
SHARP/Socle Technology
-
GP1S396HCPSF
SHARP/Socle Technology
-
LTH-301-07
Lite-On Inc.
-
RPI-352
Rohm Semiconductor
-
RPI-0226
Rohm Semiconductor
-
TCPT1300X01
Vishay Semiconductor Opto Division
-
EE-SX1320
Omron Electronics Inc-EMC Div
-
TCUT1300X01
Vishay Semiconductor Opto Division
-
EE-SX1103
Omron Electronics Inc-EMC Div
-
H22A1
Isocom Components 2004 LTD
-
EE-SX1041
Omron Electronics Inc-EMC Div
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