9.2.2.1 Slew Rate Selection

The LMG341xR070 supports slew rate adjustment through connecting a resistor from RDRV to source. The choice of RDRV will control the slew rate of the drain voltage of the device between approximately 25 V/ns and 100 V/ns. The slew rate adjustment is used to control the following aspects of the power stage:

• Switching loss in a hard-switched converter
• Radiated and conducted EMI generated by the switching stage
• Interference elsewhere in the circuit coupled from the switch node
• Voltage overshoot and ringing on the switch node due to power loop inductance and other parasitics

When increasing the slew rate, the switching power loss will decrease, as the portion of the switching period where the switch simultaneous conducts high current while blocking high voltage is decreased. However, by increasing the slew rate of the device, the other three aspects of the power stage get worse. Following the design recommendations in this datasheet will help mitigate the system-related challenges related to high slew rate. Ultimately, it is up to the power designer to ensure the chosen slew rate provides the best performance in his or her end application.