12V Input
5V LED Fault LEDs
Daughter Card
Connector
High Voltage
Input
Low side
PWM
Pin1 of J7 & J14
High side
PWM
Figure 7-2. Connector and LEDs on the LMG342X-BB-EVM
7.2 Start-Up and Operating Procedure
1. Turn on +12VDC to the LMG342X-BB-EVM. Watch the power supply for the DC current to settle down after
approximately 3 to 5 seconds.
2. Make sure all the fault LEDs are off and the 5-V LED is on.
3. Turn on +12VDC to enable the fan.
4. Turn on the function generator to output the continuous pulse, and check the deadtime of the PWM signals.
5. User proper probes for measurement. To measure the fast switching transient in the switch-node, it is
recommended to use the high-bandwidth high-voltage passive probes with minimized ground loop
connections.
6. It is recommended to add common-mode chokes to the measurement signals and to the power input/output
connections.
7. Enable the high voltage power supply and make sure to ramp the voltage up gradually from 0V to the desired
bus voltage (up to 520V). As the voltage is ramping up, the HV LED will turn on and become brighter.
Figure 7-3. Switch-Node Voltage Measurement with High-Bandwidth Probe and Pigtail Ground
Connection
Test Procedure When Paired With LMG342X-BB-EVM
16
LMG352XEVM-04X User Guide
SNOU178A – OCTOBER 2020 – REVISED FEBRUARY 2021
Copyright © 2021 Texas Instruments Incorporated
