AD5290YRMZ10-R7 Analog Devices Inc, AD5290YRMZ10-R7 Datasheet - Page 18

• Manufacturer Part Number: AD5290YRMZ10-R7
• Description: IC,Digital Potentiometer,CMOS,TSSOP,10PIN,PLASTIC
• Manufacturer: Analog Devices Inc

Specifications of AD5290YRMZ10-R7

• Taps: 256
• Resistance (ohms): 10K
• Number Of Circuits: 1
• Temperature Coefficient: 35 ppm/°C Typical
• Memory Type: Volatile
• Interface: SPI, 3-Wire Serial
• Voltage - Supply: 4.5 V ~ 30 V, ±4.5 V ~ 15 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Resistance In Ohms: 10K
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-AD5290EBZ - BOARD EVAL FOR AD5290
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD5290
APPLICATIONS
HIGH VOLTAGE DAC
AD5290 can be configured as a high voltage DAC, with out-
put voltage as high as 30 V. The circuit is shown in Figure 33.
The output is
where D is the decimal code from 0 to 255.
ADR512
PROGRAMMABLE POWER SUPPLY
With a boost regulator, such as ADP1611, AD5290 can be used
as the variable resistor at the regulator’s FB pin to provide the
programmable power supply (Figure 34). The output is
AD5290’s V
a short, and V
output slowly establishes the final value.
0.1μF
C1
R
BIAS
V
V
O
O
V
(
U1
DD
=
100kΩ
D
8.5kΩ
V
AD5290
DD
D1
. 1
)
R2
R1
=
23
DD
R1
256
DD
B
A
D
V
is derived from the output. Initially, L1 acts as
W
Figure 34. Programmable Power Supply
is one diode voltage drop below +5 V. The
×
×
AD8512
1 [
1 [
V+
V–
Figure 33. High Voltage DAC
2 .
V
R2
+
DD
V
U1A
10μF
1.23V
(
5V
C
D
22nF
×
IN
C
256
SS
1 (
)
R
−
+
2
R
R
R
U2
AB
2
1
AD5290
U2
)]
RT
FB
SS
B
]
ADP1611
GND
100kΩ
COMP
IN
SW
U1B
AD8512
R
220kΩ
L1
4.7μH
150pF
C
C
C
D1
C
10μF
OUT
V
V
OUT
Rev. B | Page 18 of 20
OUT
(4)
(5)
AUDIO VOLUME CONTROL
Because of its good THD performance and high voltage
capability, AD5290 can be used as a digital volume control.
If AD5290 is used directly as an audio attenuator or gain
amplifier, a large step change in the volume level at any arbi-
trary time can lead to an abrupt discontinuity of the audio
signal causing an audible zipper noise. To prevent this, a zero-
crossing window detector can be inserted to the CS line to
delay the device update until the audio signal crosses the
window. Since the input signal can operate on top of any
dc level rather than absolute zero volt level, zero-crossing in this
case means the signal is ac-coupled, and the dc offset level is the
signal zero reference point.
The configuration to reduce zipper noise (Figure 35) and the
results of using this configuration are shown in Figure 36. The
input is ac-coupled by C1 and attenuated down before feeding
into the window comparator formed by U2, U3, and U4B
(Figure 35). U
The upper limit of the comparator is set above its offset and,
therefore, the output pulses high whenever the input falls
between 2.502 V and 2.497 V (or 0.005 V window) in this
example. This output is AND’ e d with the chip select signal
such that the AD5290 updates whenever the signal crosses
the window. To avoid a constant update of the device, the chip
select signal should be programmed as two pulses, rather than as
one shown in Figure 36.
In Figure 35, the lower trace shows that the volume level changes
from a quarter-scale to full-scale when a signal change occurs
near the zero-crossing window.
6
is used to establish the signal zero reference.