SNAS461G May 2010 – November 2018 LM98640QML-SP
PRODUCTION DATA.
Refer to the PDF data sheet for device specific package drawings
Power for the LM98640QML-SP should be provided through a broad plane which is located on one layer adjacent to the ground plane(s). Placing the power and ground planes on adjacent layers will provide low impedance decoupling of the AFE supplies, especially at higher frequencies. The output of a linear regulator should feed into the power plane through a low impedance multi-via connection. The power plane should be split into individual power peninsulas near the AFE. Each peninsula should feed a particular power bus on the AFE, with decoupling for that power bus connecting the peninsula to the ground plane near each power/ground pin pair. Using this technique can be difficult on many printed circuit CAD tools. To work around this, 0-Ω resistors can be used to connect the power source net to the individual nets for the different AFE power buses. As a final step, the 0-Ω resistors can be removed and the plane and peninsulas can be connected manually after all other error checking is completed.