4
Practical Connections of the Evaluation Board Using Switchers for Actual Inverter Test
1. Solder actual IGBT or Power MOSFETs at Q1 for the top and bottom arms of the half-bridge inverter isolated drivers.
2. Connect an isolated DC supply 1 (voltage range 15V~30V) across V
CC2a
and V
EEa
at pin-8 and pin-5 of IC1a, respectively,
for the bottom arm. Then connect another isolated DC supply 2 (voltage range 15V~30V) across V
CC2b
and V
EEb
at
pin-8 and pin-5 of IC1b, respectively, for the top arm.
3. Connect the signal output (to drive the bottom arm of the half-bridge inverter) from the microcontroller to signal
input 1 across pins IN1+ and IN1- of CON1a of the bottom inverter arm isolated driver.
Connect another signal output (to drive the top arm of the half-bridge inverter) from the microcontroller to signal
input 2 across pins IN2+ and IN2- of CON1b of the top inverter arm isolated driver.
4. Use a multi-channel digital oscilloscope to capture the waveforms at the following points:
a. LED signal at IN1+ pin w.r.t. IN1- for the bottom arm
b. LED signal at IN2+ pin w.r.t. IN2- for the top arm (Note: IN1- and IN2- can be shorted)
c. V
ga
for the gate driving voltage of Q1a w.r.t. V
Ea
of the bottom inverter arm (differential probe needed)
d. V
gb
for the gate driving voltage of Q1b w.r.t. V
Eb
of the top inverter arm (differential probe needed)
5. Connect a power cable from the output pin (marked Load) to the inverter load.
6. Connect the high voltage cables from the top arm switcher’s collector pin to HVDC+ and from the bottom arm
switcher’s emitter pin to HVDC-, respectively, as shown. (Note: It is advised that you 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
