AD7693 Analog Devices, AD7693 Datasheet - Page 23

• Manufacturer Part Number: AD7693
• Manufacturer: Analog Devices

Specifications of AD7693

• Resolution (bits): 16bit
• # Chan: 1
• Sample Rate: 500kSPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni
• Ain Range: (2Vref) p-p,Bip (Vref) x 2
• Adc Architecture: SAR
• Pkg Type: CSP,SOP

AD7693
APPLICATION HINTS
LAYOUT
The printed circuit board that houses the AD7693 should be
designed so that the analog and digital sections are separated
and confined to certain areas of the board. The pinout of the
AD7693, with all its analog signals on the left side and all its
digital signals on the right side, eases this task.
Avoid running digital lines under the device because these
couple noise onto the die unless a ground plane under the
AD7693 is used as a shield. Fast switching signals, such as CNV
or clocks, should not run near analog signal paths. Crossover of
digital and analog signals should be avoided.
At least one ground plane should be used. It could be common
or split between the digital and analog sections. In the latter
case, the planes should be joined underneath the AD7693s.
Figure 46. Example Layout of the AD7693 (Top Layer)
The AD7693 voltage reference input REF has a dynamic input
impedance and should be decoupled with minimal parasitic
inductances. This is done by placing the reference decoupling
ceramic capacitor close to, ideally right up against, the REF and
GND pins and connecting them with wide, low impedance traces.
Finally, the power supplies VDD and VIO of the AD7693
should be decoupled with ceramic capacitors, typically 100 nF,
placed close to the AD7693 and connected using short, wide
traces to provide low impedance paths and reduce the effect of
glitches on the power supply lines.
An example of a layout following these rules is shown in
Figure 46 and Figure 47.
EVALUATING AD7693 PERFORMANCE
Other recommended layouts for the AD7693 are outlined
Figure 47. Example Layout of the AD7693 (Bottom Layer)
in the documentation of the evaluation board for the AD7693
(EVAL-AD7693CB). The evaluation board package includes
a fully assembled and tested evaluation board, documentation,
and software for controlling the board from a PC via the
EVAL-CONTROL BRD3.
Rev. A | Page 23 of 24