BT169D Silicon Controlled Rectifier (SCR) Thyristor, 400V, TO-92

The BT169D from NXP is a sensitive-gate silicon controlled rectifier (SCR), also known as a thyristor, designed for reliable switching in low-power electronic circuits. Encased in a through-hole, TO-92 plastic package, this planar passivated component offers robust voltage handling and is engineered for direct interfacing with microcontrollers, logic ICs, and other low-power gate trigger sources, simplifying control circuit design.

Its sensitive gate characteristics allow it to be triggered directly from digital logic, making it an excellent choice for modern, efficient designs where minimising component count is essential. The planar passivation process enhances its voltage ruggedness and long-term operational reliability, ensuring stable performance in a variety of demanding environments.

Key Features & Applications

This thyristor is commonly used in a wide array of applications, including:

• Ignition circuits for controlled power switching.
• Lighting ballasts for fluorescent and other discharge lamps.
• Protection circuits where reliable latching action is required.
• Portable devices, consumer electronics, and industrial power management systems.

Technical Specifications

• Average On-State Current: 500 mA.
• Maximum Gate Trigger Current: 200 µA (ensuring compatibility with low-power drivers).
• Maximum Gate Trigger Voltage: 800 mV.
• Repetitive Peak Off-State Voltage: 400 V.
• Holding Current: 5 mA.
• Non-Repetitive Peak On-State Current: 8 A (surge rating).
• On-State RMS Current: 800 mA.
• Maximum Junction Temperature: 125°C.
• Package & Mounting: Standard TO-92 (SOT54) case, designed for through-hole mounting.
• Pin Count: 3 pins.

With its combination of sensitive triggering, robust construction, and reliable switching up