BCW69LT1 Ver la hoja de datos (PDF) - Leshan Radio Company

Número de pieza

componentes Descripción

Fabricante

BCW69LT1

General Purpose Transistors

Leshan Radio Company 

LESHAN RADIO COMPANY, LTD.

BCW69LT1 BCW70LT1

104

103

102

101

100

10–1

10–2

–4

V CC = 30 V

DESIGN NOTE: USE OF THERMAL RESPONSE DATA

A train of periodical power pulses can be represented by the

I CEO

model as shown in Figure 16. Using the model and the device

thermal response the normalized effective transient thermal resis-

I

CBO

AND

I CEX @ V BE(off) = 3.0 V

tance of Figure 14 was calculated for various duty cycles.

To find Z θJA(t) , multiply the value obtained from Figure 14 by the

steady state value R θJA .

Example:

Dissipating 2.0 watts peak under the following conditions:

t 1 = 1.0 ms, t 2 = 5.0 ms. (D = 0.2)

Using Figure 14 at a pulse width of 1.0 ms and D = 0.2, the reading

of r(t) is 0.22.

–2

0 +20 +40 +60 +80 +100 +120 +140 +160

The peak rise in junction temperature is therefore

T J , JUNCTION TEMPERATURE (°C)

Figure 15. Typical Collector Leakage Current

∆T = r(t) x P (pk) x R θJA = 0.22 x 2.0 x 200 = 88°C.

For more information, see AN–569.

M13–6/6

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