SBAS486F November 2009 – February 2016 ADS41B29 , ADS41B49
PRODUCTION DATA.
A single ground plane is sufficient to give good performance, provided the analog, digital, and clock sections of the board are cleanly partitioned. See the ADS414x, ADS412x EVM User Guide, SLWU067 for details on layout and grounding.
Because the ADS41Bx9 already includes internal decoupling, minimal external decoupling can be used without loss in performance. Note that decoupling capacitors can help filter external power-supply noise, so the optimum number of capacitors depends on the actual application. Place the decoupling capacitors very close to the converter supply pins.
In addition to providing a path for heat dissipation, the PowerPAD is also electrically internally connected to the digital ground. Therefore, the exposed pad must be soldered to the ground plane for best thermal and electrical performance. For detailed information, see application notes VQFN Layout Guidelines, SLOA122, and VQFN/SON PCB Attachment, SLUA271, both available for download at the TI web site (www.ti.com).