AD5232

Manufacturer Part NumberAD5232
Description2-Channel/ 256-Position Digital Potentiometer
ManufacturerAnalog Devices
AD5232 datasheet
 


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GENERAL DESCRIPTION
The AD5232 device provides a nonvolatile, dual-channel,
digitally controlled variable resistor (VR) with 256-position
resolution. These devices perform the same electronic adjust-
ment function as a potentiometer or variable resistor. The
AD5232’s versatile programming via a microcontroller 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 microcontroller.
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 estab-
lish 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 automatically transferred 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.
All internal register contents can be read out of the serial data
output (SDO). This includes the RDAC1 and RDAC2 registers,
the corresponding nonvolatile EEMEM1 and EEMEM2 regis-
ters, and the 14 spare USER EEMEM registers available for
constant storage.
*Patent pending.
8-Bit Dual Nonvolatile Memory
Digital Potentiometer
FUNCTIONAL BLOCK DIAGRAM
CS
RDAC1
ADDR
CLK
REGISTER
DECODE
SDI
SDI
SERIAL
GND
EEMEM1
INTERFACE
RDAC2
SDO
SDO
REGISTER
WP
EEMEM
CONTROL
RDY
EEMEM2
14 BYTES
PR
USER EEMEM
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
) by one position segment of
WB
the devices’ end-to-end resistance (R
rithmic changes in wiper setting, a left/right shift command
adjusts levels in 6 dB steps, which can be useful for audio and
light alarm applications.
The AD5232 is available in a thin TSSOP-16 package. All parts
are guaranteed to operate over the extended industrial tempera-
ture range of –40 C to +85 C. An evaluation board is available,
Part Number: AD5232EVAL.
100
75
50
25
R
WB
0
0
64
128
CODE – Decimal
AD5232
AD5232
V
DD
RDAC1
A1
W1
B1
RDAC2
A2
W2
B2
V
SS
). For exponential/loga-
AB
R
WA
192
256

AD5232 Summary of contents

  • Page 1

    ... The AD5232 is available in a thin TSSOP-16 package. All parts are guaranteed to operate over the extended industrial tempera- ture range of – + evaluation board is available, Part Number: AD5232EVAL ...

  • Page 2

    ... AD5232–SPECIFICATIONS ELECTRICAL CHARACTERISTICS 100 k VERSIONS ( 10 10% and Parameter DC CHARACTERISTICS RHEOSTAT MODE – Specifications Apply to All VRs 2 Resistor Differential Nonlinearity 2 Resistor Nonlinearity Nominal Resistor Tolerance Resistance Temperature Coefficient Wiper Resistance POTENTIOMETER DIVIDER MODE — Specifications Apply to All VRs ...

  • Page 3

    ... Endurance is qualified to 100,000 cycles as per JEDEC Std. 22 method A117 and measured at V 700,000 cycles. 15 Retention lifetime equivalent at junction temperature (T will derate with junction temperature as shown in Figure 23 in the Flash/EE Memory description section of this data sheet. The AD5232 contains 9,646 transistors. Die size: 69 mil 115 mil, 7,993 sq. mil. Specifications subject to change without notice ...

  • Page 4

    ... AD5232 CLK CPOL = SDO SDI t 14 RDY NOT DEFINED, BUT NORMALLY LSB OF CHARACTER PREVIOUSLY TRANSMITTED. THE CPOL = 1 MICROCONTROLLER COMMAND ALIGNS THE INCOMING DATA TO THE POSITIVE EDGE OF THE CLOCK CLK CPOL = SDO MSB OUT SDI MSB RDY NOT DEFINED, BUT NORMALLY MSB OF CHARACTER JUST RECEIVED ...

  • Page 5

    ... ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD5232 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality ...

  • Page 6

    ... Serial Register Chip Select Active Low. Serial register operation takes place when CS returns to logic high RDY Ready. Active-high open drain output, requires pull-up resistor. Identifies completion of commands 10, and PR. PIN CONFIGURATION CLK RDY SDI SDO 3 14 AD5232 WP GND 4 13 TOP VIEW (Not to Scale ...

  • Page 7

    ... OPERATIONAL OVERVIEW The AD5232 digital potentiometer is designed to operate as a true variable resistor replacement device for analog signals that remain within the terminal voltage range of V The basic voltage range is limited digital potentiometer wiper position is determined by the RDAC register contents. The RDAC register acts as a scratch pad, register allowing as many value changes as necessary to place the potentiometer wiper in the correct position ...

  • Page 8

    ... SDO interface may require additional time delay between subsequent GND packages. If two AD5232’s are daisy-chained, 32 bits of data are required. The first 16 bits and the second 16 bits with the same format go to U1. The 16 bits are formatted to contain the 4-bit instruction, followed by the 4-bit address, then the 8 bits of data ...

  • Page 9

    ... AD5232 B0 Operation X No Operation (NOP). Do nothing. X Write contents of EEMEM(A0) to RDAC(A0) Register. This command leaves device in the Read Program power state. To return part to the idle state, perform NOP instruction #0. X SAVE WIPER SETTING. Write con- tents of RDAC(ADDR) to EEMEM(A0) Write contents of Serial Register Data Byte 0 to EEMEM(ADDR) ...

  • Page 10

    ... LSB error, which translates to a code dependent logarithmic error for odd codes only as shown in the attached plots, (see Figure 5). The plot shows the errors of the odd codes for the AD5232. LEFT SHIFT ...

  • Page 11

    ... DD SS biased diode; see Figure 8. The ground pin of the AD5232 device is primarily used as a digital ground reference, which needs to be tied to the PCBs’ common ground. The digital input logic signals to the AD5232 must be referenced to the devices’ ground pin (GND), and satisfy the logic minimum input high level and the maximum low level defined in the specification table of this data sheet ...

  • Page 12

    ... The nominal resistance (R the AD5232 VR has 256 contact points accessed by the wiper terminal, plus the B terminal contact. The 8-bit data word in the RDAC latch is decoded to select one of the 256 possible settings. ...

  • Page 13

    ... C. There is no voltage polarity restriction between terminals A, B, and W, as long as the terminal voltage (V ) stays within V TERM OPERATION FROM DUAL SUPPLIES The AD5232 can be operated from dual supplies enabling con- trol of ground-referenced ac signals. See Figure 11 for a typical circuit connection ...

  • Page 14

    ... SDO where the last 8 bits con- tain the contents of USER3 location. NOP command ensures device returns to idle power dissipation state. Analog Devices offers the AD5232EVAL board for sale to simplify evaluation of these programmable devices controlled by a personal computer via the printer port. TEST CIRCUITS Figures define the test conditions used in the product specification’ ...

  • Page 15

    ... V TA OUT IN Flash/EEMEM Reliability The Flash/EE Memory array on the AD5232 is fully qualified for two key Flash/EE memory characteristics, namely Flash/EE Memory Cycling Endurance and Flash/EE Memory Data Retention. Endurance quantifies the ability of the Flash/EE memory to be cycled through many Program, Read, and Erase cycles. In real ...

  • Page 16

    ... Performance Characteristics AD5232 2.00 1.75 1.50 1.25 INL T = – 1.00 0.75 0.50 0.25 0 –0.25 –0.50 –0.75 INL –1.00 –1.25 –1.50 –1.75 –2. 128 DIGITAL CODE 2.00 1.75 1.50 1.25 DNL T = –40 C 1.00 A 0.75 0.50 0.25 0 –0.25 –0.50 –0.75 –1.00 –1.25 –1.50 –1.75 –2. 128 DIGITAL CODE 0.20 0.15 0.10 0.05 0.00 –0.05 –0.10 –0.15 –0.20 ...

  • Page 17

    ... C A – 0.1 0.01 0.001 10 110 100 2. AD5232 f = 500kHz 10k –3dB f = 95kHz 50k – 3dB = –2.5V SS 10k 100k 1M FREQUENCY – FILTER = 22kHz 10k 50k , 100k AB 100 1k 10k 100k FREQUENCY – ...

  • Page 18

    ... AD5232 0 DATA = 80 H –6 DATA = 40 H –12 DATA = 20 H –18 DATA = 10 H –24 DATA = 08 H –30 DATA = 04 H –36 DATA = 02 H –42 DATA = +2.7V – –2.7V SS – 100mV rms –60 1k 10k FREQUENCY– DATA = 80 H –6 ...

  • Page 19

    ... AD5200 +5.5 3-wire AD8400 1 5.5 3-wire AD5260 1 5, +15 3-wire AD5241 1 3, +5.5 2-wire AD5231 1 2.75, +5.5 3-wire AD5222 2 3, +5.5 UP/ DOWN AD8402 2 5.5 3-wire AD5207 2 3, +5.5 3-wire AD5232 2 2.75, +5.5 3-wire AD5235 2 2.75, +5.5 3-wire AD5242 2 3, +5.5 2-wire AD5262 2 5, +15 3-wire AD5203 4 5.5 3-wire AD5233 4 2.75, +5.5 3-wire AD5204 4 3, +5.5 3-wire AD8403 4 5.5 3-wire AD5206 6 3, +5.5 3-wire Future Product, consult factory for latest status ...

  • Page 20

    ... AD5232 SEATING OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 16-Lead TSSOP (RU-16) 0.201 (5.10) 0.193 (4.90 0.177 (4.50) 0.169 (4.30) 0.256 (6.50) 0.246 (6.25 PIN 1 0.006 (0.15) 0.0433 (1.10) MAX 0.002 (0.05 0.0256 (0.65) 0.0118 (0.30) 0.0079 (0.20) BSC 0.0075 (0.19) PLANE 0.0035 (0.090) 0.028 (0.70) 0.020 (0.50) ...