TYPICAL APPLICATIONS
POWER DISSIPATION
cycle of 95%. This value is far from the 150ºC maximum
guaranteed junction.
CONCLUSION
Knowing the application conditions, this document
explained how to calculate power dissipation during on-state
and switching phases and the junction temperature for the
33981 when controlling a DC motor. A concrete example with
a 200 W DC motor was given in section DC Motor 200 W. The
same principle can be used for other DC motor and other
environmental conditions.
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
0
10
20
30
40
50
60
70
80
90
100
Duty cycle (%)
Figure 43. Junction Temperature vs. Duty Cycle
33981
Analog Integrated Circuit Device Data
Freescale Semiconductor
30
FREESCALE [ Freescale ]
