A good PCB layout for the LMZ14202HTZ/NOPB should include a solid ground plane, wide power traces, and a thermal relief pattern under the device to facilitate heat dissipation. TI provides a recommended PCB layout in the datasheet and application notes.
To ensure a stable and accurate output voltage, it's essential to follow the recommended capacitor selection and placement guidelines, use a low-ESR output capacitor, and minimize the loop area of the feedback network. Additionally, ensure the input voltage is within the recommended range, and the device is operated within its specified temperature range.
When selecting an input capacitor, consider the capacitor's voltage rating, ESR, and ripple current rating. The capacitor should be rated for at least 1.5 times the maximum input voltage, have a low ESR (< 1 ohm) to minimize voltage drops, and be able to handle the maximum ripple current (typically 10-20% of the maximum input current).
To minimize EMI, use a shielded inductor, keep the switching node (SW) away from sensitive nodes, use a common-mode choke or ferrite bead on the input, and ensure good PCB layout practices such as separating analog and digital grounds and using a solid ground plane.
The LMZ14202HTZ/NOPB has a high power density, so thermal design is critical. Ensure good airflow, use a heat sink if necessary, and follow the recommended PCB layout guidelines to minimize thermal resistance. The device's thermal pad should be connected to a solid ground plane to facilitate heat dissipation.
LMZ14202HTZ/NOPB datasheet
by Texas Instruments
