33886_11 Datasheet, PDF (18/27 Pages) Freescale Semiconductor, Inc – TTL / CMOS Compatible Inputs PWM Frequencies up to 10 kHz

FUNCTIONAL DEVICE OPERATION
PERFORMANCE
PERFORMANCE
The 33886 is designed for enhanced thermal
performance. The significant feature of this device is the
exposed copper pad on which the power die is soldered. This
pad is soldered on a PCB to provide heat flow to ambient and
also to provide thermal capacitance. The more copper area
on the PCB, the better the power dissipation and transient
behavior will be.
Example Characterization on a double-sided PCB:
bottom side area of copper is 7.8 cm²; top surface is 2.7 cm²
(see Figure 21); grid array of 24 vias 0.3 mm in diameter.
Figure 22 shows the thermal response with the device
soldered on to the test PCB described in Figure 21.
100
10
Rth (¬¨ÐóC
1
0,1
0,001
0,01
0,1
1
10
t, Time (s)
100
1000
10000
Figure 22. 33886 Thermal Response
Top Side
Bottom Side
Figure 21. PCB Test Layout
33886
18
Analog Integrated Circuit Device Data
Freescale Semiconductor