ADS6143IRHB25 Datasheet, PDF (55/67 Pages) Texas Instruments – 14-BITS, 125/105/80/65 MSPS ADC WITH DDR LVDS/CMOS OUTPUTS

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ADS6145, ADS6144
ADS6143, ADS6142
SLWS198B – JULY 2007 – REVISED MARCH 2008
BOARD DESIGN CONSIDERATIONS
Grounding
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 EVM User Guide (SLWU028) for details on layout and grounding.
Supply Decoupling
As the ADS614X already include 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 would depend on the actual application. The decoupling capacitors should be placed very
close to the converter supply pins.
It is recommended to use separate supplies for the analog and digital supply pins to isolate digital switching
noise from sensitive analog circuitry. In case only a single 3.3-V supply is available, it should be routed first to
AVDD. It can then be tapped and isolated with a ferrite bead (or inductor) with decoupling capacitor, before being
routed to DRVDD.
Exposed Thermal Pad
It is necessary to solder the exposed pad at the bottom of the package to a ground plane for best thermal
performance. For detailed information, see application notes QFN Layout Guidelines (SLOA122) and QFN/SON
PCB Attachment (SLUA271).
Copyright © 2007–2008, Texas Instruments Incorporated
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