# BCP 28/29, BCP 28/49 - Darlington Transistors Summary

## Device Overview

These documents outline specifications and characteristics for the BCP 28 and BCP 29, and BCP 28/49 Darlington transistors. These are used in various applications.

## Electrical Characteristics

️· Maximum Ratings: Defined based on operating conditions.
️· DC Characteristics:
- Collector Cutoff Current (ICBO): Ranges from 100nA, varying slightly with temperature.
- Emitter-Base Cutoff Current (IEB0): Approximately 100nA.
- Collector Saturation Voltage (VCEsat): Around 1V at specified collector and emitter currents.
- Base-Emitter Saturation Voltage (VBEsat): Approximately 1.5V.
- DC Current Gain (hFE): Varies significantly, ranging from 4000 to 20000, depending on collector current.
️· Frequency Characteristics:
- Transition Frequency (fT): Around 200 MHz, dependent on collector current.
- Collector-Base Capacitance (CCB0): Approximately 8 pF.
️· Thermal Resistance
* Junction to Ambient (RthA): 93 K/W

* Junction to Soldering Point (RthS): 17 K/W

## Operational Notes

️· For accurate performance, devices should be mounted on a printed circuit board with a 3mm copper pad for heat dissipation.
️· The tests use pulses of 300us with a duty cycle of 2% for certain test conditions

## Recommended Complementary Transistors

️· BCP 29 - Complementary to BCP 28
️· BCP 49 - Complementary to BCP 28