Zetex AN21-1 Application Note Bipolar Transistor Considerations for Battery Powered Equipment

About this manual

This application note provides an overview of Zetex's bipolar transistor technology, focusing on selection criteria, performance comparison with MOSFETs, and benefits for low‑voltage, battery‑powered applications. It discusses silicon utilization, drive voltage requirements, on‑state loss, reverse‑blocking capability, and pricing considerations.

The document includes tables of performance features, low‑voltage transistor part selections (e.g., FMMT717, ZTX788B), terminology comparisons between bipolar and MOSFET devices, and thermal/characteristic curves to aid designers in choosing the appropriate transistor for portable systems.

What's inside

• Introduction
• Bipolar vs MOSFET
• Performance Features (Table 1)
• Matrix Geometry
• Voltage Rating Parameters
• Low Voltage Transistors for Battery Systems (Table 2)
• Bipolar/MOSFET Terminology (Table 3)
• Thermal Characteristics
• Appendix A – Example Datasheet

Specifications

Frequently asked questions

How does silicon utilization of bipolar transistors compare to MOSFETs?

Bipolar transistors claim the highest silicon utilization, enabling a smaller silicon area for a given on‑state loss compared with MOSFETs.