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FOD817B3SD

ONFOD817B3SD

onsemi
Optoisolator Transistor Output 5000Vrms 1 Channel 4-SMD
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Overview

The FOD817B3SD is a single-channel phototransistor optocoupler designed to provide 5000Vrms electrical isolation between input and output stages. It consists of a gallium arsenide (GaAs) infrared emitting diode driving a silicon phototransistor in a surface-mount 4-SMD package. This component is commonly used to protect sensitive low-voltage logic from high-voltage transients in power supplies and industrial control systems.

Why Choose This Part

This device offers a high isolation voltage of 5000Vrms and a 70V maximum output voltage, making it robust for high-voltage switching. With a low Vce saturation of 200mV and a typical rise time of 4us, it provides efficient signal transfer with minimal power loss in the output transistor. The wide operating temperature range of -55 to 110 degrees Celsius ensures reliability in harsh industrial environments.

Applications

Switch Mode Power Supplies
Providing feedback isolation for regulation loops to maintain galvanic separation between primary and secondary sides.
Programmable Logic Controllers (PLCs)
Protecting MCU inputs and outputs from industrial noise and voltage spikes on the factory floor.
Digital Logic Ground Isolation
Eliminating ground loops in communication interfaces like UART, SPI, or I2C across different voltage domains.
System Appliances
Isolating control signals in consumer electronics and white goods where high-voltage AC power is present.

Key Specifications

Input Type DC
Output Type Transistor
Mounting Type Surface Mount
Package / Case 4-SMD, Gull Wing
Number of Channels 1
Voltage - Isolation 5000Vrms
Vce Saturation (Max) 200mV
Operating Temperature -55degC ~ 110degC
Rise / Fall Time (Typ) 4us, 3us
Voltage - Output (Max) 70V
Supplier Device Package 4-SMD
Current - Output / Channel 50mA
Current Transfer Ratio (Max) 260% @ 5mA
Current Transfer Ratio (Min) 130% @ 5mA
Voltage - Forward (Vf) (Typ) 1.2V
Current - DC Forward (If) (Max) 50 mA

Getting Started

To implement the FOD817B3SD, calculate the series resistor for the input LED based on a typical 5mA run current to ensure reliable switching. Ensure the output transistor is biased correctly within the 70V limit and consider the 3us fall time for high-speed signal requirements. When designing the PCB, maintain proper creepage and clearance distances under the 4-SMD package to preserve the 5000Vrms isolation integrity.

Also Consider

LTV-817 Lite-On Inc. - An alternative 4-SMD phototransistor optocoupler often chosen for cost-sensitive high-volume applications.

Categories

Industrial & Automation > Industrial Communication