Gan Systems GS66502B-EVBDB, User Manual

Page: 16 / 33

Follow the instructions below to quickly get started with your evaluation of GaN E-HEMT. Equipment
and components you will need:

Four-channel oscilloscope with 500MHz bandwidth or higher

high bandwidth (500MHz or higher) passive probe

high bandwidth (500MHz) high voltage probe (>600V)

AC/DC current probe for inductor current measurement

12V DC power supply

Signal generator capable of creating testing pulses

High voltage power supply (0-400VDC) with current limit.

External power inductor (recommend toroid inductor 50-200uH)
1.
Check the JP1 on daughter board GS665XXX-EVBDB. Use a copper foil and solder to short JP1.
2. Install GS665XXX-EVBDB on the mother board. Press all the way down until you feel a click. Connect
probe between VGL and VSL for gate voltage measurement.
3. Set up the mother board:
a. Connect 12VDC bias supply to J1.
b. Connect PWM input gate signal (0-5V) to J7. If it is generated from a signal generator ensure
the output mode is high-Z mode.
c. Set J4 to OFF position and J7 to INT.
d. Set High voltage (HV) DC supply voltage to 0V and ensure the output is OFF. Connect HV
supply to CON2 and CON6.
e. Use HV probe between TP6 and TP5 for Vds measurement.
f. Connect external inductor between CON1 and CON3. Use current probe to measure inductor
current IL.
4. Set up and check PWM gate signal:
a. Turn-on 12VDC power.
b. Check the 2 LEDs on the daughter board. They should be turned on indicating the isolated
9V is present.
c. Set up signal generator to create the waveforms as shown in Figure 14. Use equation I
SW
=
(V
DS
*T
ON1
) / L to calculate the pulse width of the first pulse and ensure the Isw_max is
≤
30A at
400VDC.
d. Set the operation mode to either single trigger or Burst mode with repetition period of 100ms.
e. Turn on the PWM output and check on the oscilloscope to make sure the VGL waveform is
present and matches the PWM input.
5. Power-on:
a. Turn on the output of the HV supply. Start with low voltage and slowly ramp the voltage up
until it reaches 400VDC. During the ramping period closely observe the the voltage and
current waveforms on the oscilloscope.
6. Power-off:
a. After the test is complete, slowly ramp down the HV supply voltage to 0V and turn off the
output. Then turn off the 12V bias supply and signal generator output.