BC857A-TP

Overview

The BC857A-TP is a single PNP bipolar junction transistor manufactured by Micro Commercial Components. It utilizes silicon technology and is housed in an SOT-23-3 surface-mount package. Key electrical ratings include a maximum collector-emitter voltage of 45 V, a collector-base voltage of 50 V, and an emitter-base voltage of 5 V. The device supports a continuous collector current of -100 mA with a power dissipation capacity of 310 mW. It features a transition frequency of 100 MHz and operates within a temperature range of -55°C to +150°C.

Feature Summary

• Single PNP configuration for compact circuit integration
• Silicon epitaxial planar construction for reliability
• SOT-23-3 surface-mount footprint for automated assembly

Applications

• General-purpose switching circuits
• Small-signal amplification stages
• Audio pre-amplifier inputs

Procurement Notes

Verify the specific datasheet version for the BC857A-TP to confirm exact hFE binning limits and thermal resistance values. Ensure the ordering suffix matches the required packaging format, such as cut tape or reel, as these affect handling procedures. Confirm RoHS compliance status directly from the manufacturer's documentation before finalizing procurement specifications.

Selection Notes

Select this component when a low-voltage PNP switch or amplifier is required in a small surface-mount form factor. The 45V rating suits low-power logic interfacing. Compare the 310mW dissipation against thermal constraints in dense PCB layouts. Verify that the -100mA current limit meets the load requirements without exceeding safe operating area boundaries during peak operation cycles.

Part Context

This part belongs to the BC857 series of general-purpose PNP transistors. It shares the same physical package and basic voltage/current ratings with variants like BC857B and BC857C, differing primarily in DC current gain (hFE) classification. The BC857A typically offers a tighter gain tolerance compared to standard grades, making it suitable for applications requiring consistent amplification factors.

Replacement Considerations

Direct pin-compatible substitutes include BC857B-TP and BC857C-TP from the same manufacturer. Cross-brand equivalents such as the 2N3906 are available but require package adaptation. Verify that any replacement maintains the 45V VCEO rating and SOT-23 footprint to ensure mechanical fit.