BSR57

Overview

The onsemi BSR57 is a general-purpose NPN silicon epitaxial planar transistor housed in a compact SOT-23 surface-mount package. It provides a maximum collector current of 100 mA and withstands a collector-emitter voltage of 40 V. The device features a power dissipation rating of 350 mW and operates within a temperature range of -55°C to +150°C. With a transition frequency of 100 MHz, it supports efficient signal amplification and switching applications in low-power electronic circuits.

Feature Summary

• Utilizes an epitaxial planar silicon construction for reliable performance
• Designed for general-purpose amplification and switching tasks
• Offers high thermal stability with extended operating temperature limits

Applications

• General-purpose signal amplification
• Low-power switching circuits
• Driver stages for small loads

Procurement Notes

Verify the specific suffix against official datasheets to confirm pinout orientation and gain binning. Confirm RoHS compliance status and ensure the supplier provides traceable documentation. Check for obsolescence notices as this component may be subject to lifecycle changes.

Selection Notes

Select this component when a small-footprint NPN transistor is required for space-constrained designs. Ensure the application current remains below 100 mA and voltage stays under 40 V. Consider the SOT-23 package compatibility with automated assembly processes.

Part Context

This part belongs to the BSR series of general-purpose NPN transistors from onsemi. It serves as a surface-mount alternative to through-hole devices like the BC547, offering similar electrical characteristics in a smaller form factor suitable for modern PCB layouts.

Replacement Considerations

Direct substitutes include the BSR17A or BC547BTA, provided the package type matches the design constraints. Verify that replacement parts meet the same voltage, current, and thermal specifications.