AD5233 Datasheet, PDF (1/14 Pages) Analog Devices – Nonvolatile Memory Digital Potentiometers

PRELIMINARY TECHNICAL DATA
a
Nonvolatile Memory
Digital Potentiometers
AD5231/AD5232/AD5233
FEATURES
Nonvolatile Memory Preset Maintains Wiper Settings
AD5231 Single, 1024 Position Resolution
AD5232 Dual, 256 Position Resolution
AD5233 Quad, 64 Position Resolution
10K, 50K, 100K Ohm Terminal Resistance
Linear or Log taper Settings
Increment/Decrement Commands, Push Button Command
SPI Compatible Serial Data Input with Readback Function
+3 to +5V Single Supply or ±2.5V Dual Supply Operation
User EEMEM nonvolatile memory for constant storage
APPLICATIONS
Mechanical Potentiometer Replacement
Instrumentation: Gain, Offset Adjustment
Programmable Voltage to Current Conversion
Programmable Filters, Delays, Time Constants
Line Impedance Matching
Power Supply Adjustment
DIP Switch Setting
GENERAL DESCRIPTION
The AD5231/AD5232/AD5233 family provides a single-
/dual-/quad-channel, digitally controlled variable resistor (VR)
with resolutions of 1024/256/64 positions respectively. These
devices perform the same electronic adjustment function as a
potentiometer or variable resistor. The AD523X’s versatile
programming via a Micro Controller allows multiple modes of
operation and adjustment.
In the direct program mode a predetermined setting of the
RDAC register can be loaded directly from the micro controller.
Another key mode of operation allows the RDAC register to be
refreshed with the setting previously stored in the EEMEM
register. When changes are made to the RDAC register to
establish a new wiper position, the value of the setting can be
saved into the EEMEM by executing an EEMEM save
operation. Once the settings are saved in the EEMEM register
these values will be transferred automatically to the RDAC
register to set the wiper position at system power ON. Such
operation is enabled by the internal preset strobe and the preset
can also be accessed externally.
The basic mode of adjustment is the increment and decrement
command controlling the present setting of the Wiper position
setting (RDAC) register. An internal scratch pad RDAC register
can be moved UP or DOWN, one step of the nominal terminal
resistance between terminals A-and-B. This linearly changes the
wiper to B terminal resistance (R_WB) by one position segment of
the device's end-to-end resistance (R_AB). For
exponential/logarithmic changes in wiper setting, a left/right
shift command adjusts levels in +/-6dB steps, which can be
useful for sound and light alarm applications.
The AD523X are available in the thin TSSOP package. All
parts are guaranteed to operate over the extended industrial
temperature range of -40°C to +85°C.
FUNCTIONAL BLOCK DIAGRAMS
CS
CLK
SDI
GND
SDI
ADDR
DECODE
S E R IA L
IN TER FACE
AD5231
V_DD
RDAC1
RDAC1
R E G IS T E R
A₁
W₁
EEMEM1
B₁
SDO
SDO
D IG ITAL 2
WP
RDY
EEMEM
CONTROL
R E G IS T E R
D IG ITAL
2
O₁
OUTPUT
BUFFER
O₂
EEMEM2
PR
28 BYTES
V _SS
USER EEMEM
CS
CLK
SDI
GND
SDI
ADDR
DECODE
SER IAL
IN TERFAC E
AD5232
V _DD
RDAC1
RDAC1
R EG ISTER
A₁
W₁
EEMEM1
B₁
SDO
SDO
RDAC2
RDAC2
R EG ISTER
A₂
WP
EEMEM
W₂
RDY
CONTROL
EEMEM2
B₂
PR
14 BYTES
USER EEMEM
V _SS
CS
CLK
SDI
SDO
WP
RDY
GND
O₁
O₂
PR
SDI
ADDR
DECODE
SER IAL
IN TERFAC E
SDO
EEMEM
CONTROL
11 BYTES
USER EEMEM
D IGITAL
OUTPUT
BUFFER
2
D IGITAL 5
R EG ISTER
EEMEM5
AD5233
V _DD
RDAC1
RDAC1
R EG ISTER
A₁
W₁
EEMEM1
B₁
RDAC2
RDAC2
R EG ISTER
A₂
W₂
EEMEM2
B₂
RDAC3
RDAC3
R EG ISTER
A₃
W₃
EEMEM3
B₃
RDAC4
RDAC4
R EG ISTER
A₄
W₄
EEMEM4
B₄
V _SS
REV PrF, 22 MAR '01
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