Datasheet

AN823
Vishay Siliconix
www.vishay.com
2
Document Number: 71743
27-Feb-04
255 − 260_C
1X4_C/s (max) 3-6_C/s (max)
10 s (max)
Reflow Zone
Pre-Heating Zone
3_C/s (max)
140 − 170_C
Maximum peak temperature at 240_C is allowed.
FIGURE 3. Solder Reflow Temperature and Time Durations
60-120 s (min)
217_C
60 s (max)
THERMAL PERFORMANCE
A basic measure of a device’s thermal performance is the
junction-to-case thermal resistance, Rq
jc
, or the
junction-to-foot thermal resistance, Rq
jf
. This parameter is
measured for the device mounted to an infinite heat sink and
is therefore a characterization of the device only, in other
words, independent of the properties of the object to which the
device is mounted. Table 1 shows the thermal performance
of the TSOP-6.
TABLE 1.
Equivalent Steady State Performance—TSOP-6
Thermal Resistance Rq
jf
30_C/W
SYSTEM AND ELECTRICAL IMPACT OF
TSOP-6
In any design, one must take into account the change in
MOSFET r
DS(on)
with temperature (Figure 4).
0.6
0.8
1.0
1.2
1.4
1.6
−50 −25 0 25 50 75 100 125 150
V
GS
= 4.5 V
I
D
= 6.1 A
On-Resistance vs. Junction Temperature
T
J
− Junction Temperature (_C)
FIGURE 4. Si3434DV
r
DS(on)
− On-Resiistance
(Normalized)