AD8403ARZ10-REEL Datasheet, PDF (1/32 Pages) Analog Devices – 1-/2-/4-Channel Digital Potentiometers

FEATURES
256-position variable resistance device
Replaces 1, 2, or 4 potentiometers
1 kΩ, 10 kΩ, 50 kΩ, 100 kΩ
Power shutdown—less than 5 μA
3-wire,SPI-compatible serial data input
10 MHz update data loading rate
2.7 V to 5.5 V single-supply operation
Qualified for automotive applications
APPLICATIONS
Mechanical potentiometer replacement
Programmable filters, delays, time constants
Volume control, panning
Line impedance matching
Power supply adjustment
GENERAL DESCRIPTION
The AD8400/AD8402/AD8403 provide a single-, dual-, or
quad-channel, 256-position, digitally controlled variable resistor
(VR) device.¹ These devices perform the same electronic adjust-
ment function as a mechanical potentiometer or variable
resistor. The AD8400 contains a single variable resistor in the
compact SOIC-8 package. The AD8402 contains two independent
variable resistors in space-saving SOIC-14 surface-mount
packages. The AD8403 contains four independent variable
resistors in 24-lead PDIP, SOIC, and TSSOP packages. Each
part contains a fixed resistor with a wiper contact that taps the
fixed resistor value at a point determined by the digital code
loaded into the controlling serial input register. The resistance
between the wiper and either endpoint of the fixed resistor
varies linearly with respect to the digital code transferred into
the VR latch. Each variable resistor offers a completely
programmable value of resistance between the A terminal and
the wiper or the B terminal and the wiper. The fixed A-to-B
terminal resistance of 1 kΩ, 10 kΩ, 50 kΩ, or 100 kΩ has a ±1%
channel-to-channel matching tolerance with a nominal
temperature coefficient of 500 ppm/°C. A unique switching
circuit minimizes the high glitch inherent in traditional
switched resistor designs, avoiding any make-before-break
or break-before-make operation.
(continued on Page 3)
1 _{The terms digital potentiometer, VR, and RDAC are used interchangeably.}
Rev. E
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1-/2-/4-Channel
Digital Potentiometers
AD8400/AD8402/AD8403
FUNCTIONAL BLOCK DIAGRAM
V_DD
DGND
SDI
CLK
CS
AD8403
DAC
SELECT
1
2
3
A1, A0 ⁴
2
10-BIT
SERIAL 8
LATCH
D
CK Q RS
8-BIT ^{8 RDAC1}
LATCH
CK RS
SHDN
RDAC2
8-BIT ⁸
LATCH
CK RS
SHDN
RDAC3
8-BIT ⁸
LATCH
CK RS
SHDN
RDAC4
8-BIT ⁸
LATCH
CK RS
SHDN
A1
W1
B1
AGND1
A2
W2
B2
AGND2
A3
W3
B3
AGND3
A4
W4
B4
AGND4
SDO
RS SHDN
Figure 1.
100
R_WA
75
R_WB
50
25
0
0
64
128
192
255
CODE (Decimal)
Figure 2. RWA and RWB vs. Code
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