VisIC V22N65A GaN Half Bridge Evaluation Board
User Manual USG-022650-004
All the above is subject to T’s & C’s agreed by the parties – VER 3.4
Preliminary Data Sheet: VisIC, Ltd. reserves the right to make design improvement changes at any time.
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User Guide USG-022650-001
Page | 9
The board is equipped with a short and full serial number providing information about the version of
board schematic, PCB, BOM and mechanical assembly.
3.2.
Terminals
The board is equipped with four screw-type power terHV, -HV, OUT, COIL (See Fig. 1, Fig. 2a).
They are dedicated to connections of the power components like power supply, load, banks of
capacitors, inductor.
The BNC connector PWM IN1 is dedicated to control the power switches. The high level (above 2.4V)
on the input causes the upper switch to conduct (ON state) and the lower switch to be non-conducting
(OFF state). The low level (below 0.8V) on the input causes the upper switch to be OFF and the lower
switch to be ON.
The terminal P16 is meant for connection of the 12V auxiliary power supply. It is dedicated to power
the control, driver circuits and cooler system as well.
The header P17 is used to provide power to the cooler system.
3.3.
Test points
The half bridge test points (see Fig. 2 a): +HV-DC (TP30), MID-PIONT (TP31), -HV-DC (TP32) are
connected with the drain of the upper GaN Switch, the mid-point of the half bridge and the source of
the lower GaN Switch respectively. These test points provide a way to observe the voltage waveforms
on the switches, measure the Rise and Fall times. It is recommended to use for measurements high
bandwidth-high voltage differential probes (for reference see Appendix 11).
The second group are “GaN Switch” driver test points. There are the test points for the high side
switch (G-HS, GND-HS, +12-HS) and three test points for the low side switch (G-LS, GND-LS, +12-LS).
Using the G-xS/GND-xS test points make it possibility to observe the shape of the Gate signals and to
measure the delay time and dead time between high side/low side Gate signals. It is recommended
to use “short grounds” for any gate measurements
1
. Using +12-xS/GND-xS test point is dedicated to
observing voltage on the output of the driver power supplies.
Two “GND” test points on the “primary” side (see Fig. 3) are dedicated to measurements and
debugging of the non-isolated primary circuit.
1
Please pay attention on proper isolation of measurement equipment during any gate
measurements: local grounds of “All switch” drivers (see Fig. 1) should stay floating.
