9.3 Do's and Don'ts
The successful use of GaN devices in general and the LMG341xR050 in particular depends on proper use of the device. When using the LMG341xR050, Do the following:
- Read and fully understand the datasheet, including the application notes and layout recommendations.
- Use a four-layer board and place the return power path on an inner layer to minimize power-loop inductance.
- Use small, surface-mount bypass and bus capacitors to minimize parasitic inductance.
- Use the proper size decoupling capacitors and locate them close to the IC as described in the Layout Guidelines section.
- Use a signal isolator to supply the input signal for the low side device. If not, ensure the signal source is connected to the signal GND plane which is tied to the power source only at the LMG341xR050 IC.
- Use the FAULT pin to determine power-up state and to detect overcurrent and overtemperature events and safely shut off the converter.
To avoid issues in your system when using the LMG341xR050, Do not do the following:
- Use a single-layer or two-layer PCB for the LMG341xR050 as the power-loop and bypass capacitor inductances will be excessive and prevent proper operation of the IC.
- Reduce the bypass capacitor values below the recommended values.
- Allow the device to experience drain transients above 600 V as they may damage the device.
- Allow significant third-quadrant conduction when the device is OFF or unpowered, which may cause overheating. Self-protection feature cannot protect the device in this mode of operation.
- Ignore the FAULT pin output.