To achieve optimal electrical and thermal
performance, an optimized PCB layout is required. Figure 10-1 through Figure 10-4 shows a typical PCB layout. Some considerations for an optimized layout are:
- Use large copper areas for
power planes (PVIN, VOUT, and PGND) to minimize conduction loss and thermal
stress.
- Place ceramic input and
output capacitors close to the device pins to minimize high frequency
noise.
- Locate additional output
capacitors between the ceramic capacitor and the load.
- Keep AGND and PGND separate
from one another. The connection is made internal to the device.
- Place RVSEL,
RADJ, RRT, RMODE, and CSS as
close as possible to their respective pins.
- Use multiple vias to connect
the power planes (PVIN, VOUT, and PGND) to internal layers.