Part Number: LMG2100R044
Other Parts Discussed in Thread: LMG2100EVM-078,
Dear Support Team,
I am currently developing a 6.78 MHz half-bridge inverter based on the LMG2100R044 GaN power stage. The circuit design closely follows the reference design of the LMG2100EVM-078 evaluation module.
However, during testing, I observed unexpectedly high no-load power consumption. With a DC input voltage of 30 V and no load connected, the input current reaches approximately 0.25 A, corresponding to about 7.5 W of no-load power loss. This results in significant heating of the LMG2100R044 device.
For the gate-drive network, both the high-side and low-side GaN FETs use 1 Ω gate resistors, which is not consistent with the EVM design. I am wondering whether the excessive no-load current could be related to the gate resistor values or other switching-loss mechanisms at 6.78 MHz operation.
Could you please provide guidance on the following points?
- Is a no-load current of approximately 0.25 A at 30 V input normal for a 6.78 MHz half-bridge inverter based on LMG2100R044?
- Could the 1 Ω gate resistors contribute significantly to the observed power loss and device heating?
- Are there any recommended methods to optimize the gate-drive network and reduce switching losses at 6.78 MHz?
For your convenience, I have attached the schematic and PCB layout of my design. （ HB.rar ）I hope these documents will assist your team in analyzing the issue and providing recommendations for optimization.
Any suggestions or recommendations would be greatly appreciated.
Thank you for your support, and I look forward to your response.
Best regards,
LianLi
Southwest Jiaotong University
