QT851

Overview

The QT851 is a single-channel optocoupler manufactured by QT Brightek. It features a high-power phototransistor output driven by an infrared emitting diode. The device provides electrical isolation with a voltage rating of 5000Vrms. It is housed in a 4-pin DIP package with a pin spacing of 0.300 inches (7.62mm). This component is designed for applications requiring robust signal transmission across isolated circuits.

Feature Summary

• High power phototransistor output configuration
• Electrical isolation capability up to 5000Vrms
• Single channel operation

Applications

• General purpose signal isolation
• Microprocessor interface circuits
• Solid state relay drivers

Procurement Notes

Verify the specific datasheet version for the QT851 to confirm absolute maximum ratings and thermal characteristics. Ensure the 4-pin DIP package dimensions match the target PCB layout requirements. Confirm that the 5000Vrms isolation rating meets the safety standards required for the intended application environment.

Selection Notes

Select the QT851 when high isolation voltage is required in a standard DIP package. Consider the phototransistor output type for compatibility with logic inputs. Evaluate the current transfer ratio specifications against the load requirements to ensure proper switching performance in the circuit design.

Part Context

QT Brightek manufactures optoelectronic components including LEDs and optocouplers. The QT851 belongs to their optocoupler product line, which utilizes transistor or photovoltaic outputs. These devices are used to isolate electronic signals between different voltage domains while maintaining data integrity.

Replacement Considerations

Consult official manufacturer substitution guides for verified equivalents. Generic replacements may differ in isolation voltage or current transfer ratio.