Communication Concepts FM-1KW Broadcast Application Note - Manual (Page 7)

MRFE6VP61K25H MRFE6VP61K25HS FM Broadcast
7
RF Reference Design Data
Freescale Semiconductor
Figure 10 shows the internal diagram of the ITC55100B
tester. The tester controller activates the pulse generator to
turn on the device under test (DUT) through the limiting and
terminating resistor, R
G
, creating a very clean gate pulse
waveform. This pulse waveform tests the maximum energy
dissipation capability of the DUT by stressing it under
various, controlled energy levels. This is accomplished by
attaching an unclamped inductive load to the device’s drain
and source connection and then increasing both the load
current and load voltage up until the point that the DUT
failure is achieved. Using this test method for power devices
ensures proper operation in circuits used to drive inductive
loads that may possibly cause an avalanche mode stress on
the DUT. The final maximum energy dissipation capability
rating, in joules, is calculated by the following equation:
E = 1
2
× L × I 2
where L is the load inductance value and I is the peak current
within the load inductor.
Figure 10. Internal Diagram of the ITC55100B Tester
Controller
Measurement
Pulse
Generator
Kelvin
Isolator
R
G
50 Ω
R
G
50 Ω
DUT
L
D
I
D
Monitor
High Speed
Switch
Freewheeling
Diode
V
D
+
--
The highest energy level the MRFE6VP61K25H/HS
device passed is shown in Figure 11. During the course of
this testing, the device dissipated over 5.77 joules of energy
over a discharge time of 859 μsec, while reaching a
maximum current of 76 A and a maximum voltage of
197 volts. (These load voltage and current values are taken
under short discharge durations to keep the thermal
dissipation issues out of the ruggedness equation.)
Figure 11. Voltage and Current Curves During Energy Discharge
• Max Voltage = 196.8 Vdc
• End Voltage = 167.5 Vdc
• Energy = 5.766 J (full device)
• ID
peak
= 76 A