For best operational performance of the device, use good printed circuit board (PCB) layout practices, including the following guidelines:
- Noise from the amplifier can propagate into other
analog circuits through the power pins of the
amplifiers. Use bypass capacitors to reduce the
coupled noise by providing low-impedance power
sources local to the analog circuitry.
- Connect low-ESR, 0.1-µF ceramic bypass capacitors between each supply pin and ground, placed as close to the device as possible. A single bypass capacitor from V+ to ground is applicable for single-supply applications.
- Separate grounding for analog and digital portions of circuitry is one of the simplest and most-effective methods of noise suppression. One or more layers on multilayer PCBs are usually devoted to ground planes. A ground plane helps distribute heat and reduces EMI noise pickup. Make sure to physically separate digital and analog grounds paying attention to the flow of the ground current.
- To reduce parasitic coupling, run the input
traces as far away from the supply or output traces as possible. If these traces
cannot be kept separate, crossing the sensitive trace perpendicular is much
better than running in parallel with the noisy trace.
- Place the external components as close to the device as possible.
- Keep the length of input traces as short as possible. Always remember that the input traces are the most sensitive part of the circuit.
- Consider a driven, low-impedance guard ring around the critical traces. A guard ring can significantly reduce leakage currents from nearby traces that are at different potentials.
- For best performance, clean the PCB following
board assembly.
- Any precision integrated circuit may experience
performance shifts due to moisture ingress into
the plastic package. Following any aqueous PCB
cleaning process, bake the PCB to remove moisture
introduced into the device packaging during the
cleaning process. A low-temperature, post-cleaning
bake at 85°C for 30 minutes is sufficient for most
circumstances.