The slew rate of LMG3425R050 can be adjusted between approximately 20 V/ns and 150V/ns by connecting a resistor, R_RDRV, from the RDRV pin to GND. The RDRV pin is a high-impedance node if a large R_RDRV resistor is used. Therefore it can be susceptible to coupling from the drain or other fast-slewing high-voltage nodes if it is not well-shielded. This will manifest itself as an unstable switching dv/dt and in extreme cases transient faults due to the RDRV being detected as open. Shielding the pin in the layout should be a priority, however if this coupling is still a problem, a cap of up to 1nF from RDRV to GND can be added to stabilize the pin voltage.

The slew rate affects GaN device performance in terms of:

• Switching loss
• Voltage overshoot
• Noise coupling
• EMI emission

Generally, high slew rates provide low switching loss, but high slew rates can also create higher voltage overshoot, noise coupling, and EMI emissions. Following the design recommendations in this data sheet helps mitigate the challenges caused by a high slew rate. The LMG3425R050 offers circuit designers the flexibility to select the proper slew rate for the best performance of their applications.