EL814 Series 4 Pin Phototransistor Optocoupler DIP-4

EL814 Series 4 Pin Phototransistor Optocoupler DIP-4 is a fundamental electronic component that provides essential electrical isolation between two separate circuits using light. This optocoupler integrates an infrared Light Emitting Diode (LED) on the input side with a high-sensitivity phototransistor on the output side, all housed within a compact 4-pin Dual In-line Package. Consequently, it allows a low-voltage control signal to safely switch or sense a higher-voltage or electrically noisy circuit without a direct galvanic connection. The EL814 series, in particular, offers a high current transfer ratio (CTR), ensuring efficient signal transfer across the isolation barrier. Therefore, designers widely choose this optocoupler for safety-critical applications requiring robust noise immunity and maximum circuit protection.

Key Features:

• High Isolation Voltage: Provides excellent input-to-output isolation, typically rated at 5000 V_RMS, preventing ground loops and protecting sensitive control circuitry.
• Phototransistor Output: The output features a reliable phototransistor, capable of switching moderate DC loads or driving the input of a subsequent logic gate.
• High Current Transfer Ratio (CTR): Offers high efficiency, meaning a small input current to the LED generates a proportionally large current at the output transistor.
• Low Saturation Voltage: The output transistor exhibits low collector-emitter saturation voltage (V_CE(sat)), improving efficiency when used as a switch.
• Standard DIP-4 Package: The industry-standard 4-pin package ensures easy mounting and compatibility with common PCB layouts.

Technical Specifications:

• Input Type: Infrared Emitting Diode (LED)
• Output Type: Phototransistor
• Isolation Voltage (V_ISO): 5000 V_RMS minimum
• Collector-Emitter Voltage (V_CEO): 80 V max
• Collector Current (I_C): 50 mA max
• Current Transfer Ratio (CTR): Typically 50% to 600% depending on the specific model suffix (e.g., EL814A, B, C, D).
• Operating Temperature Range: −55°C to +110°C

Mechanical Specifications:

• Package Type: DIP-4 (Through-Hole)
• Leads: Tinned Copper Alloy
• Package Material: Epoxy Resin (UL 94 V-0 Flammability Rated)
• Pin Count: 4

Dimensions:

• Body Length: ≈ 4.6 mm
• Body Width: ≈ 3.5 mm
• Pin Pitch (Between pins): 2.54 mm (0.1 inch)
• Row Spacing (Between rows): 7.62 mm (0.3 inch)
• Total Height: ≈ 3.5 mm (Seated height)

Pinout and Wiring:

• Pin 1 (Anode): Connect to the positive terminal of the input control signal (via a current-limiting resistor).
• Pin 2 (Cathode): Connect to the ground/negative terminal of the input control signal.
• Pin 3 (Emitter): Connect to the load or ground reference of the output circuit.
• Pin 4 (Collector): Connect to the positive supply voltage (V_CC) of the output circuit, typically through a pull-up resistor (R_L).

Datasheet Reference:

• Download Everlight EL814 Optocoupler Datasheet

Commonly Used in:

• Switch Mode Power Supplies (SMPS): Essential for providing feedback and isolation in voltage regulation circuits.
• Microcontroller Input Interfaces: Safely isolates the MCU from noisy DC motor drivers or high-voltage sensors.
• Digital Logic Isolation: Used to couple signals between systems operating at different ground potentials or noise levels.

Applications:

• Noise Suppression: Effectively eliminates noise and transient voltage coupling between circuits.
• I/O Isolation in PLCs: Provides input/output isolation in programmable logic controllers (PLCs) and industrial controls.
• Data Communications: Used for signal coupling in digital communication lines where common mode noise is a concern.

Equivalent Models:

• PC817 (Sharp/Vishay): This is the most common equivalent; furthermore, the PC817 generally offers a comparable pinout and isolation rating.
• LTV-814 (Lite-On): A direct cross-reference part number providing the same electrical and mechanical specifications.
• 4N25 / 4N35: While functional, these older general-purpose optocouplers might not match the high CTR and speed of the EL814 series.

Package Includes:

• 1 x EL814 Series 4 Pin Phototransistor Optocoupler DIP-4