onsemi

MMBT3904WT1

MMBT3904WT1 Description

The MMBT3904WT1 from onsemi is an NPN bipolar junction transistor (BJT) housed in a compact SOT-323 package, designed for general-purpose amplification and switching applications. With a 40V collector-emitter voltage (V_CEO) and 200mA continuous collector current (I_C), it offers reliable performance in low-to-medium power circuits. This transistor is REACH unaffected and complies with ECCN EAR99 and HTSUS 8541.29.0095, making it suitable for global markets. Although marked as Obsolete, it remains a robust choice for legacy designs due to its proven stability and Moisture Sensitivity Level (MSL) 1 (Unlimited) rating, ensuring durability in humid environments.

MMBT3904WT1 Features

• High Voltage Tolerance: Supports up to 40V V_CEO, ideal for circuits requiring moderate voltage handling.
• Compact SOT-323 Package: Saves board space compared to bulkier alternatives like SOT-23.
• Low Saturation Voltage: Enhances efficiency in switching applications.
• Wide Operating Temperature Range: Suitable for industrial and consumer electronics.
• MSL 1 Rating: No baking required before assembly, simplifying production workflows.

MMBT3904WT1 Applications

This transistor excels in:

• Signal Amplification: Audio preamps, sensor interfaces, and RF stages.
• Switching Circuits: Relay drivers, LED controllers, and logic-level converters.
• Portable Electronics: Space-constrained devices like wearables and IoT modules.
• Legacy System Maintenance: Repair or replication of older designs requiring discontinued components.

Conclusion of MMBT3904WT1

The MMBT3904WT1 is a versatile NPN transistor balancing performance, size, and reliability. Its 40V/200mA capability and SOT-323 footprint make it a pragmatic choice for amplification and switching tasks in compact designs. While obsolete, its MSL 1 compliance and REACH unaffected status ensure longevity in existing applications. Engineers seeking a proven, space-efficient BJT for legacy or low-power systems will find this component a dependable solution.