AN1923 Motorola / Freescale Semiconductor, AN1923 Datasheet - Page 5

• Manufacturer Part Number: AN1923
• Description: AN1923 Application Note Mounting Method with Mechanical Fasteners for the MRF19090 and Similar Packages
• Manufacturer: Motorola / Freescale Semiconductor

RESULTS
Volts and 135 Watts of dissipated power. At 90 Watts of RF
output power at 40% efficiency the dissipated power is 135
Watts. A peak case temperature of more than 90 C was
achieved as measured by a thermocouple directly under the
heatsink of each device. The MRF19090 device has the
MOTOROLA SEMICONDUCTOR APPLICATION INFORMATION
The assemblies were cycled under DC conditions at 26
Figure 10. Power as a Function of Time for One Cycle
Figure 9. Power Life Test Board
specified junction to case resistance (
on this, the junction temperature at 135 Watts power
dissipation will be approximately 190 C when the sink
temperature is 90 C. The temperature rise is calculated
based on the
devices were powered at a 50% duty cycle for 2000 cycles
representing 1000 hours of cycling.
JC
plus the interface resistance of 0.1 C/W. The
JC
)
of 0.65 C/W. Based
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