MJE13002

NPN EPITAXIAL SILICON TRANSISTOR

UNISONICTECHNOLOGIESCO.,LTD

5 of 9

www.unisonic.com.tw

QW-R204-014.C

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 SWITCHMODE power

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

must be made on each wave form to determine the total switching time, For this reason, the following new terms have

been defined.

An enlarged portion of the inductive switching waveforms is shown in Figure 1 to aid in the visual identity of

these terms.

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 from AN-222:

PSWT=1/2 VccIc (tc)f

In general, trv + tfi tc. However, at lower test currents this relationship may not be valid.

≒

As is common with most switching transistor, 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 specifications

which make this a “SWITCHMODE” transistor are the inductive switching speeds (tc and tsv) which are guaranteed at

100°C.

RESISTIVE SWITCHING PERFORMANCE

0.02

Fig 3. Turn-Off Time

0.03

0.05

2

10

7

5

1

0.7

0.1

0.07

0.2

0.1

0.3

0.5 0.7 1

3

2

0.5

0.3

0.2

Vcc=125V

0.02

Fig 2. Turn-On Time

0.03

0.05

20

2

1

0.7

0.2

0.1

0.02

0.07

0.2

0.1

0.3

0.5 0.7

1

0

0.5

0.3

0.07

0.05

0.03

Vcc=125V

td @ VBE(off)=5V