Texas Instruments provides a recommended PCB layout in the LM3421Q1MH/NOPB datasheet, which includes a thermal pad connected to a copper plane on the PCB to dissipate heat. Additionally, it is recommended to use a 2-ounce copper PCB and to keep the thermal pad away from other components to minimize thermal resistance.
To ensure reliable startup and shutdown, it is recommended to use a soft-start circuit to limit the inrush current during startup, and to use a voltage supervisor or reset IC to monitor the output voltage and reset the system during power-up and power-down sequences.
The maximum output capacitance that can be used with the LM3421Q1MH/NOPB is not explicitly stated in the datasheet, but it is generally recommended to use a maximum of 10uF to 22uF of output capacitance to ensure stability and prevent oscillations.
To protect the LM3421Q1MH/NOPB from input voltage transients and surges, it is recommended to use a TVS (Transient Voltage Suppressor) diode or a voltage clamp circuit at the input to limit the voltage to within the recommended operating range.
The recommended input filter configuration for the LM3421Q1MH/NOPB is a pi-filter (L-C-R) or an LC filter with a ferrite bead or a common-mode choke to filter out high-frequency noise and ripple.
LM3421Q1MH/NOPB datasheet
by Texas Instruments
