64-Position Up/Down
Control Digital Potentiometer
AD5227
FEATURES
64-position digital potentiometer
FUNCTIONAL BLOCK DIAGRAM
V
DD
10 kΩ, 50 kΩ, 100 kΩ end-to-end terminal resistance
Simple up/down digital or manual configurable control
Midscale preset
Low potentiometer mode tempco = 10 ppm/°C
Low rheostat mode tempco = 35 ppm/°C
Ultralow power, IDD = 0.4 μA typ and 3 μA max
Fast adjustment time, ts = 1 μs
Chip select enable multiple device operation
Low operating voltage, 2.7 V to 5.5 V
Automotive temperature range, −40°C to +105°C
Compact thin SOT-23-8 (2.9 mm × 3 mm) Pb-free package
AD5227
A
CS
6-BIT UP/DOWN
CONTROL
LOGIC
U/D
W
B
CLK
GND
POR
MIDSCALE
WIPER
REGISTER
Figure 1.
APPLICATIONS
Mechanical potentiometer and trimmer replacements
LCD backlight, contrast, and brightness controls
Portable electronics level adjustment
Programmable power supply
Digital trimmer replacements
Automatic closed-loop control
GENERAL DESCRIPTION
The AD5227 is Analog Devices’ latest 64-step up/down control
digital potentiometer1. This device performs the same electronic
adjustment function as a 5 V potentiometer or variable resistor.
Its simple 3-wire up/down interface allows manual switching or
high speed digital control. The AD5227 presets to midscale at
The AD5227 is available in a compact thin SOT-23-8 (TSOT-8)
Pb-free package. The part is guaranteed to operate over the
automotive temperature range of −40°C to +105°C.
Users who consider EEMEM potentiometers should refer to
some recommendations in the Applications section.
power-up. When
is enabled, the devices changes step at
CS
Table 1. Truth Table
every clock pulse. The direction is determined by the state of
CLK
↓
↓
Operation1
CS
U/D
D
the U/ pin (see Table 1). The interface is simple to activate by
0
0
1
0
1
X
RWB Decrement
RWB Increment
No Operation
any host controller, discrete logic, or manually with a rotary
encoder or pushbuttons. The AD5227’s 64-step resolution, small
footprint, and simple interface enable it to replace mechanical
potentiometers and trimmers with typically 6× improved
resolution, solid-state reliability, and design layout flexibility,
resulting in a considerable cost savings in end users’ systems.
X
1 RWA increments if RWB decrements and vice versa.
1 The terms digital potentiometer and RDAC are used interchangeably.
Rev. B
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