27.12 MHz, CLASS-E, 400W RF Generator using a Microsemi DRF1200 Driver/MOSFET Hybrid
4
1. Hardware and power sequencing requirements
• Cooling requirement: Testing is recommended to be performed using a water cooling
system.
• Sequential steps for Turn-On/Turn-Off of Power Supplies.
a. Turn on Driver power supply PS_2 (10V via JP1).
b. Then, turn on MOSFET supply (PS HV) and slowly increase to 50V (via
JP2).
c. Then, turn on SW1 on the pulse circuit.
d. While monitoring the RF power from power meter and output waveform of
the Drain, ramp up MOSFET power supply (VDD) to the values per Table 1
making sure that output is stable for each supply voltage before proceeding
to the next higher voltage.
• To turn-off, turn power supplies off in the reverse order.
If RF output waveform, Vds and/or RF power level from power meter fluctuate, immediately
shut down VDD for safety, and determine fault before resuming test.
Performance
1. Data Summary
100 1.56 100 64
120 1.67 140 70
140 1.8 183 73
180 2.09 282 75
200 2.25 337 75
220 2.44 401 75
Table 1 · Power Sequencing Data Summary
Table 1 shows the effects of varying the PS HV(V
DD)/IDD on MOSFET current, RF power and
efficiency, The chart of Efficiency vs. Pout is shown in Figure 3. The efficiency is calculated using
RF power output and DC input power of the power MOSFET.
