ZHCSPF6B february 2022 – may 2023 LMQ66410 , LMQ66420 , LMQ66430
PRODUCTION DATA
As previously mentioned, TI recommends using one of the middle layers as a solid ground plane. A ground plane provides shielding for sensitive circuits and traces as well as a quiet reference potential for the control circuitry. Connect the GND pin to the ground planes using vias next to the bypass capacitors. The GND trace, as well as the VIN and SW traces, must be constrained to one side of the ground planes. The other side of the ground plane contains much less noise; use for sensitive routes.
TI recommends providing adequate device
heat-sinking by having enough copper near the GND pin. See
Figure 9-13 for example layout. Use as much copper as possible, for system ground plane, on
the top and bottom layers for the best heat dissipation. Use a four-layer board with
the copper thickness for the four layers, starting from the top as: 2 oz / 1 oz / 1
oz / 2 oz. A four-layer board with enough copper thickness, and proper layout,
provides low current conduction impedance, proper shielding, and lower thermal
resistance.