4
Practical Connections of the Evaluation Board Using IGBT or SiC/GaN MOSFET for Actual Inverter Test
1. Solder a IGBT or SiC/GaN MOSFET at Q1(or Q2) for top and bottom arms of the half bridge inverter isolated drivers
2. Connect a +5V DC isolated supply1 5V and GND terminals of CON1 for both arms of the isolated drivers;
3. Connect another isolated DC supply2 (voltage range from 15V~30V) across Vcc2a and Veea at pin-7 and pin-5 of IC2a
respectively for bottom arm
4. Connect the signal output (meant to drive the bottom arm of half-bridge inverter) from microcontroller to signal
input 1 across pin IN1+ and IN1- of CON1a of bottom inverter arm isolated driver
5. Connect the signal output (meant to drive the top arm of half-bridge Inverter) from microcontroller to signal
input 2 across pin IN2+ and IN2- of CON1b of top inverter arm isolated driver;
Note: Signal input 2 should be 180
°
out of phase with reference to signal input 1; Check that Vcc2b (voltage close to Vcc2a)
is generated through the bootstrap components D3b and R6
6. Use a multi-channel digital oscilloscope to capture the waveforms at the following points –
a. LED signal at IN1+ pin with reference to GND for bottom arm
b. LED signal at IN2+ pin with reference to GND for top arm
c. Vga for the gate driving voltage of Q1a(or Q2a) with reference to Vea of bottom inverter arm (differential probe
needed)
d. Vgb for the gate driving voltage of Q1b(or Q2b) with reference to Veb of top inverter arm (differential probe
needed)
7. Connect a power cable from output pin (marked Load) to the inverter load
8. Connect the high voltage cables from top arm SiC/GaN MOSFET drain pin (or IGBT's Collector pin) to HVDC+ and from
bottom arm SiC/GaN MOSFET source pin (or IGBT's Emitter pin) to HVDC- respectively as shown.
Note: It is advised to enable the current limiting function of the HV Power Source supplying the High Voltage DC Bus voltage
during this test to protect the Inverter and its driver circuitries.
Figure 4. Connection of Evaluation Board in Actual Applications
M
icr
oc
on
tro
lle
r
IN1+
IN1 - Signal Input 1
+5
V
Gn
d
DC
Su
pp
ly
1
IN2+
IN2 - Signal Input 2
PowerMos
Mounted
PowerMos
Mounted
1
1
2
3
15~30V
+
-
DC Supply2
4
5
15~30V
+
-
5
6a
6b
6c
6d
Load
7
HVDC+
HVDC -
8
8
K1
50
10
1
W349
W349
06JAN15
06JAN15
