AD5228 Analog Devices, Inc., AD5228 Datasheet - Page 14

• Manufacturer Part Number: AD5228
• Description: 32-position Manual Up/down Control Potentiometer
• Manufacturer: Analog Devices, Inc.

AD5228
POWER-UP AND POWER-DOWN SEQUENCES
Because of the ESD protection diodes that limit the voltage
compliance at Terminals A, B, and W (Figure 39), it is important
to power on V
and W. Otherwise, the diodes are forward-biased such that V
is powered on unintentionally and can affect other parts of the
circuit. Similarly, V
power-on sequence is in the following order: GND, V
V
as long as they are powered on after V
and PD pins can be logic high or floating, but they should not
be logic low during power-on.
A/B/W
. The order of powering V
DD
before applying any voltage to Terminals A, B,
DD
should be powered down last. The ideal
A
, V
B
, and V
DD
. The states of the PU
W
is not important
DD
, and
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DD
LAYOUT AND POWER SUPPLY BIASING
It is always a good practice to use compact, minimum lead
length layout design. The leads to the input should be as direct
as possible with a minimum conductor length. Ground paths
should have low resistance and low inductance. It is also good
practice to bypass the power supplies with quality capacitors.
Low ESR (equivalent series resistance) 1 µF to 10 µF tantalum
or electrolytic capacitors should be applied at the supplies to
minimize any transient disturbance and to filter low frequency
ripple. Figure 39 illustrates the basic supply bypassing configu-
ration for the AD5228.
V
DD
Figure 40. Power Supply Bypassing
+
C2
10µF
C1
0.1µF
V
AD5228
DD
GND