ad5323bru-reel Analog Devices, Inc., ad5323bru-reel Datasheet - Page 24

• Manufacturer Part Number: ad5323bru-reel
• Description: 2.5 V To 5.5 V, 230 ?a, Dual Rail-to-rail Voltage Output 8-/10-/12-bit Dacs
• Manufacturer: Analog Devices, Inc.

AD5303/AD5313/AD5323
POWER SUPPLY BYPASSING AND GROUNDING
In any circuit where accuracy is important, careful considera-
tion of the power supply and ground return layout helps to
ensure the rated performance. The printed circuit board on
which the AD5303/AD5313/AD5323 are mounted should be
designed so that the analog and digital sections are separated
and confined to certain areas of the board. If the AD5303/
AD5313/AD5323 are in a system where multiple devices
require an AGND-to-DGND connection, the connection
should be made at one point only. The star ground point
should be established as close as possible to the AD5303/
AD5313/AD5323. The AD5303/AD5313/AD5323 should
have ample supply bypassing of 10 μF in parallel with 0.1 μF
on the supply located as close to the package as possible, ideally
right up against the device. Use 10 μF capacitors that are of the
tantalum bead type. The 0.1 μF capacitor should have low
effective series resistance (ESR) and effective series inductance
SCLK
SYNC
SDO
DIN
t
8
DB15
SCLK
t
t
4
SDO
6
t
INPUT WORD FOR DAC N
5
UNDEFINED
Figure 47. Daisy-Chaining Timing Diagram
t
3
t
Rev. B | Page 24 of 28
1
t
2
DB0
t
12
V
t
13
IL
(ESI), like the common ceramic types that provide a low
impedance path to ground at high frequencies to handle
transient currents due to internal logic switching.
The power supply lines of the AD5303/AD5313/AD5323 should
use as large a trace as possible to provide low impedance paths
and reduce the effects of glitches on the power supply line. Fast
switching signals such as clocks should be shielded with digital
ground to avoid radiating noise to other parts of the board, and
should never be run near the reference inputs. Avoid crossover
of digital and analog signals. Traces on opposite sides of the
board should run at right angles to each other. This reduces
the effects of feedthrough through the board. A microstrip
technique is by far the best, but is not always possible with a
double-sided board. In this technique, the component side of
the board is dedicated to the ground plane while signal traces
are placed on the solder side.
DB15
DB15
V
IH
INPUT WORD FOR DAC (N+1)
INPUT WORD FOR DAC N
t
DB0
DB0
14
t
15