MMBT5087L Datasheet, PDF (6/7 Pages) ON Semiconductor – Low Noise Transistor

MMBT5087L
1.0
0.7
0.5
D = 0.5
0.3
0.2
0.2
0.1
0.1
0.07
0.05
0.05
0.02
0.03
0.02
0.01
SINGLE PULSE
0.01
0.01 0.02 0.05 0.1 0.2 0.5 1.0 2.0
P_(pk)
FIGURE 16
t₁
t₂
DUTY CYCLE, D = t₁/t₂
D CURVES APPLY FOR POWER
PULSE TRAIN SHOWN
READ TIME AT t₁ (SEE AN569/D)
Z_qJA(t) = r(t) • R_qJA
T_J(pk) − T_A = P_(pk) Z_qJA(t)
5.0 10 20 50 100 200
t, TIME (ms)
500 1.0 k 2.0 k 5.0 k 10 k 20 k 50 k 100 k
Figure 14. Thermal Response
10⁴
V_CC = 30 V
10³
I_CEO
10²
10¹
I_CBO
AND
10⁰
I_CEX @ V_BE(off) = 3.0 V
10^-1
10^-2
-4 -2
00
0 + 20 + 40 + 60 + 80 + 100 + 120 + 140 + 160
T_J, JUNCTION TEMPERATURE (°C)
Figure 15. Typical Collector Leakage Current
DESIGN NOTE: USE OF THERMAL RESPONSE DATA
A train of periodical power pulses can be represented by
the model as shown in Figure 16. Using the model and the
device thermal response the normalized effective transient
thermal resistance of Figure 14 was calculated for various
duty cycles.
To find Z_qJA(t), multiply the value obtained from Figure
14 by the steady state value R_qJA.
Example:
Dissipating 2.0 watts peak under the following conditions:
t₁ = 1.0 ms, t₂ = 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.
The peak rise in junction temperature is therefore
DT = r(t) x P_(pk) x R_qJA = 0.22 x 2.0 x 200 = 88°C.
For more information, see ON Semiconductor Application
Note AN569/D, available from the Literature Distribution
Center or on our website at www.onsemi.com.
www.onsemi.com
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