The following images illustrate examples of a PCB
layout with the TMUX7348F and TMUX7349F. Some key considerations are as follows:
- For reliable operation, connect a decoupling capacitor ranging from 0.1 µF to 10
µF between VDD and VSS to GND. We recommend a 0.1 µF and 1 µF
capacitor, placing the lowest value capacitor as close to the pin as possible. Make sure
that the capacitor voltage rating is sufficient for the VDD and
VSS supplies.
- Multiple decoupling capacitors can be
used if there is a lot of noise in the system. For example, a 0.1-µF and 1-µF can be
placed on the supply pins. If multiple capacitors are used, then placing the lowest
value capacitor closest to the supply pin is recommended.
- Keep the input lines as short as possible.
- Use a solid ground plane to help distribute heat and reduce electromagnetic interference (EMI) noise pickup.
- Do not run sensitive analog traces in parallel with digital traces. Avoid crossing digital and analog traces if possible, and only make perpendicular crossings when necessary.