AD7366BRUZ-5 View Datasheet(PDF) - Analog Devices

Part Name

Description

Manufacturer

AD7366BRUZ-5

True Bipolar Input, 12-/14-Bit, 2-Channel, Simultaneous Sampling SAR ADCs

Analog Devices 

APPLICATION HINTS

LAYOUT AND GROUNDING

The printed circuit board that houses the AD7366-5/AD7367-5

should be designed so that the analog and digital sections are

confined to their own separate areas of the board. This design

facilitates the use of ground planes that can be easily separated.

To provide optimum shielding for ground planes, a minimum

etch technique is generally the best option. All AGND pins on

the AD7366-5/AD7367-5 should be connected to the AGND

plane. Digital and analog ground pins should be joined in only

one place. If the AD7366-5/AD7367-5 are in a system where

multiple devices require an AGND and DGND connection, the

connection should still be made at only one point. A star point

should be established as close as possible to the ground pins on

the AD7366-5/AD7367-5.

Good connections should be made to the power and ground

planes. This can be done with a single via or multiple vias for

each supply and ground pin.

Avoid running digital lines under the AD7366-5/AD7367-5

devices because this couples noise onto the die. However, the

analog ground plane should be allowed to run under the

AD7366-5/AD7367-5 to avoid noise coupling. The power

supply lines to the AD7366-5/AD7367-5 should use as large

a trace as possible to provide low impedance paths and reduce

the effects of glitches on the power supply line.

AD7366-5/AD7367-5

To avoid radiating noise to other sections of the board, com-

ponents such as clocks with fast switching signals, should be

shielded with digital ground and should never be run near the

analog inputs. Avoid crossover of digital and analog signals. To

reduce the effects of feedthrough within the board, traces should

be run at right angles to each other. A microstrip technique is

the best method, but its use may not be possible with a double-

sided board. In this technique, the component side of the board

is dedicated to ground planes, and signals are placed on the

other side.

Good decoupling is also important. All analog supplies should

be decoupled with 10 μF tantalum capacitors in parallel with

0.1 μF capacitors to AGND. To achieve the best results from

these decoupling components, they must be placed as close as

possible to the device, ideally right up against the device. The

0.1 μF capacitors should have a low effective series resistance

(ESR) and low effective series inductance (ESI), such as is typical

of common ceramic and surface mount types of capacitors. These

low ESR, low ESI capacitors provide a low impedance path to

ground at high frequencies to handle transient currents due to

internal logic switching.

EVALUATING THE AD7366-5/AD7367-5

Evaluation boards for the AD7366 and AD7367, the

EVAL-AD7366CBZ and EVAL-AD7367CBZ, can also be

used to evaluate the performance of the AD7366-5 and

AD7367-5, respectively. These evaluation boards can be

used in conjunction with EVAL-CONTROL BRD2 to

provide a full-featured evaluation platform.

Rev. B | Page 27 of 28

Share Link: