July 2007

Rev 2

1/11

11

Table 1.

Device summary

Order codes

Marking

Package

Packaging

BULD741T4

BULD741

DPAK

Tape & reel

BULD741-1

BULD741

IPAK

Tube

BULD741

High voltage fast-switching NPN power transistor

Features

■

High voltage capability

■

Low spread of dynamic parameters

■

Minimum lot-to-lot spread for reliable operation

■

Very high switching speed

Description

The device is manufactured using high voltage

Multi-Epitaxial Planar technology for high

switching speeds and high voltage capability.

Thanks to an increased intermediate layer, it has

an intrinsic ruggedness which enables the

transistor to withstand an high collector current

level during breakdown condition, without using

the transil protection usually necessary in typical

converters for lamp ballast.

Applications

■

Electronic ballast for fluorescent lighting

■

Switch mode power supplies.

Figure 1.

Internal schematic diagram

DPAK

1

3

3

2

1

IPAK

TO-252

TO-251

www.st.com