MJE13003-P

NPN SILICON TRANSISTOR

UNISONICTECHNOLOGIESCO.,LTD

6 of 9

www.unisonic.com.tw

QW-R204-027.F

SWITCHING TIMES NOTE

In resistive switching circuits, rise, fall, and storage times have been defined and apply to both current and voltage

waveforms since they are in phase. However, for inductive loads, which are common to switch mode power supplies

and hammer drivers, current and voltage waveforms are not in phase. Therefore, separate measurements must be

made on each waveform to determine the total switching time. For this reason, the following new terms have been

defined.

For the designer, there is minimal switching loss during storage time and the predominant switching power losses

occur during the crossover interval and can be obtained using the standard equation:

As is common with most switching transistors, resistive switching is specified at 25°C and has become a

benchmark for designers. However, for designers of high frequency converter circuits, the user oriented

100°C.

RESISTIVE SWITCHING PERFORMANCE

0.02

0.05

0.5

2

1

0.7

0.2

0.1

0.02

0.1

0.2

0.3

20

Vcc=125V

0.07

0.02

0.05

1

10

7

2

1

0.5

0.2

0.1

0.2

0.5

2

0.3

0.1

0.5

0.3

0.05

0.03

0.03

0.07

0.7 10

Vcc=125V

5

3

0.7

0.03

0.07

0.3

0.7

Fig.2 Turn-On Time

Fig.3 Turn-Off Time

Fig.4 Thermal Response