EVAL-AD5252EBZ

Manufacturer Part NumberEVAL-AD5252EBZ
DescriptionEVALUATION BOARD
ManufacturerAnalog Devices Inc
EVAL-AD5252EBZ datasheet
 

Specifications of EVAL-AD5252EBZ

Main PurposeDigital PotentiometerUtilized Ic / PartAD5252
Lead Free Status / RoHS StatusLead free / RoHS CompliantSecondary Attributes-
Embedded-Primary Attributes-
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FEATURES
AD5251: Dual 64-position resolution
AD5252: Dual 256-position resolution
1 kΩ, 10 kΩ, 50 kΩ, 100 kΩ
1
Nonvolatile memory
stores wiper setting w/write protection
Power-on refreshed with EEMEM settings in 300 μs typ
EEMEM rewrite time = 540 μs typ
Resistance tolerance stored in nonvolatile memory
12 extra bytes in EEMEM for user-defined information
2
I
C-compatible serial interface
2
Direct read/write access of RDAC
and EEMEM registers
Predefined linear increment/decrement commands
Predefined ±6 dB step change commands
Synchronous or asynchronous dual-channel update
Wiper setting readback
4 MHz bandwidth—1 kΩ version
Single supply 2.7 V to 5.5 V
Dual supply ±2.25 V to ±2.75 V
2 slave address decoding bits allow operation of 4 devices
100-year typical data retention, T
= 55°C
A
Operating temperature: –40°C to +85°C
APPLICATIONS
Mechanical potentiometer replacement
General-purpose DAC replacement
LCD panel V
adjustment
COM
White LED brightness adjustment
RF base station power amp bias control
Programmable gain and offset control
Programmable voltage-to-current conversion
Programmable power supply
Sensor calibrations
GENERAL DESCRIPTION
The AD5251/AD5252 are dual-channel, I
ory, digitally controlled potentiometers with 64/256 positions,
respectively. These devices perform the same electronic adjust-
ment functions as mechanical potentiometers, trimmers, and
variable resistors. The parts’ versatile programmability allows
multiple modes of operation, including read/write access in the
RDAC and EEMEM registers, increment/decrement of resistance,
resistance changes in ±6 dB scales, wiper setting readback, and
extra EEMEM for storing user-defined information, such as
memory data for other components, look-up table, or system
identification information.
Rev. B
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
Dual 64-/256-Position I
Memory Digital Potentiometers
V
DD
V
SS
DGND
WP
SCL
SDA
AD0
AD1
The AD5251/AD5252 allow the host I
any of the 64-/256-step wiper settings in the RDAC registers
and store them in the EEMEM. Once the settings are stored,
they are restored automatically to the RDAC registers at system
power-on; the settings can also be restored dynamically.
The AD5251/AD5252 provide additional increment,
decrement, +6 dB step change, and –6 dB step change in
synchronous or asynchronous channel update mode. The
increment and decrement functions allow stepwise linear
adjustments, with a ± 6 dB step change equivalent to doubling
or halving the RDAC wiper setting. These functions are useful
for steep-slope, nonlinear adjustments, such as white LED
brightness and audio volume control.
The AD5251/AD5252 have a patented resistance-tolerance
storing function that allows the user to access the EEMEM and
obtain the absolute end-to-end resistance values of the RDACs
for precision applications.
2
C®, nonvolatile mem-
The AD5251/AD5252 are available in TSSOP-14 packages in
1 kΩ, 10 kΩ, 50 kΩ, and 100 kΩ options. All parts are
guaranteed to operate over the –40°C to +85°C extended
industrial temperature range.
1
The terms nonvolatile memory and EEMEM are used interchangeably.
2
The terms digital potentiometer and RDAC are used interchangeably.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113 © 2004–2009 Analog Devices, Inc. All rights reserved.
2
C Nonvolatile
AD5251/AD5252
FUNCTIONAL BLOCK DIAGRAM
RDAC EEMEM
RDAC1
EEMEM
RAB
REGIS-
POWER-ON
TOL
TER
REFRESH
DATA
RDAC3
2
I
C
REGIS-
SERIAL
TER
CONTROL
INTERFACE
COMMAND
DECODE LOGIC
ADDRESS
DECODE LOGIC
POWER-
ON RESET
CONTROL LOGIC
Figure 1.
2
C controllers to write
www.analog.com
RDAC1
A1
W1
B1
RDAC3
A3
W3
B3
AD5251/
AD5252

EVAL-AD5252EBZ Summary of contents

  • Page 1

    FEATURES AD5251: Dual 64-position resolution AD5252: Dual 256-position resolution 1 kΩ, 10 kΩ, 50 kΩ, 100 kΩ 1 Nonvolatile memory stores wiper setting w/write protection Power-on refreshed with EEMEM settings in 300 μs typ EEMEM rewrite time = 540 μs ...

  • Page 2

    AD5251/AD5252 TABLE OF CONTENTS Features .............................................................................................. 1 Applications ....................................................................................... 1 General Description ......................................................................... 1 Functional Block Diagram .............................................................. 1 Revision History ............................................................................... 2 Electrical Characteristics ................................................................. 3 1 kΩ Version .................................................................................. 3 10 kΩ, 50 kΩ, 100 kΩ Versions .................................................. ...

  • Page 3

    ELECTRICAL CHARACTERISTICS 1 kΩ VERSION ± 10 ± 10 Table 1. Parameter DC CHARACTERISTICS— RHEOSTAT MODE Resolution 2 Resistor Differential Nonlinearity Resistor Nonlinearity 2 Nominal ...

  • Page 4

    AD5251/AD5252 Parameter DIGITAL INPUTS AND OUTPUTS Input Logic High Input Logic Low Output Logic High (SDA) Output Logic Low (SDA) WP Leakage Current A0 Leakage Current Input Leakage Current (Other than WP and A0) 5 Input Capacitance POWER SUPPLIES Single-Supply ...

  • Page 5

    VERSIONS ± 10 ± 10 Table 2. Parameter Symbol DC CHARACTERISTICS— RHEOSTAT MODE Resolution N 2 Resistor Differential Nonlinearity ...

  • Page 6

    AD5251/AD5252 Parameter Symbol POWER SUPPLIES Single-Supply Power Range V DD Dual-Supply Power Range V DD Positive Supply Current I DD Negative Supply Current I SS EEMEM Data Storing Mode I DD_STORE Current EEMEM Data Restoring Mode I DD_RESTORE 6 Current ...

  • Page 7

    INTERFACE TIMING CHARACTERISTICS All input control voltages are specified with t characteristics are measured using both V Table 3. Interface Timing and EEMEM Reliability Characteristics (All Parts) Parameter INTERFACE TIMING SCL Clock Frequency t Bus-Free Time Between Stop and Start ...

  • Page 8

    AD5251/AD5252 ABSOLUTE MAXIMUM RATINGS T = 25°C, unless otherwise noted. A Table 4. Parameter V to GND GND GND Maximum Current I ...

  • Page 9

    PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Table 5. Pin Function Descriptions Pin No. Mnemonic Description 1 V Positive Power Supply Pin. Connect +2 for single supply or ±2.7 V for dual supply, where ...

  • Page 10

    AD5251/AD5252 TYPICAL PERFORMANCE CHARACTERISTICS 1.0 0.8 0 –40°C, +25°C, +85°C, +125°C A 0.4 0.2 0 –0.2 –0.4 –0.6 –0.8 –1 128 160 CODE (Decimal) Figure 3. R-INL vs. Code 1.0 0 –40°C, ...

  • Page 11

    DATA = 0x00 200 25°C 180 A 160 140 120 V = 5.5V DD 100 T = 25° (V) BIAS ...

  • Page 12

    AD5251/AD5252 0 –6 0x80 –12 0x40 –18 0x20 –24 0x10 –30 0x08 –36 0x04 –42 0x02 –48 0x01 –54 –60 10 100 1k 10k FREQUENCY (Hz) Figure 15. AD5252 Gain vs. Frequency vs. Code 0x80 –6 0x40 –12 ...

  • Page 13

    R = 1kΩ 25° 10kΩ 50kΩ 100kΩ CODE ...

  • Page 14

    AD5251/AD5252 INTERFACE SCL SDA INTERFACE GENERAL DESCRIPTION FROM MASTER TO SLAVE FROM SLAVE TO MASTER S = START CONDITION P = STOP CONDITION A = ACKNOWLEDGE ...

  • Page 15

    I C INTERFACE DETAIL DESCRIPTION FROM MASTER TO SLAVE FROM SLAVE TO MASTER S = START CONDITION P = STOP CONDITION A = ACKNOWLEDGE (SDA LOW NOT ACKNOWLEDGE (SDA HIGH) R/W = READ ENABLE AT HIGH AND ...

  • Page 16

    AD5251/AD5252 RDAC/EEMEM Write Setting the wiper position requires an RDAC write operation. The single write operation is shown in Figure 27, and the consecutive write operation is shown in Figure 28. In the consecutive write operation, if the RDAC is ...

  • Page 17

    SLAVE ADDRESS 1 READ Figure 29. RDAC Current Read (Restricted to Previously Selected Address Stored in the Register) S SLAVE ADDRESS 0 A INSTRUCTION AND ADDRESS ...

  • Page 18

    AD5251/AD5252 RDAC/EEMEM Quick Commands The AD5251/AD5252 feature 12 quick commands that facilitate easy manipulation of RDAC wiper settings and provide RDAC- to-EEMEM storing and restoring functions. The command format is shown in Figure 31, and the command descriptions are shown ...

  • Page 19

    Table 10. Address Table for Reading Tolerance (CMD/ REG = 0, EE/ RDAC = ...

  • Page 20

    AD5251/AD5252 2 I C-COMPATIBLE 2-WIRE SERIAL BUS 1 SCL AD1 AD0 R SDA START BY FRAME 1 MASTER SLAVE ADDRESS BYTE 1 SCL SDA 0 START BY MASTER The first byte of the AD5251/AD5252 is ...

  • Page 21

    THEORY OF OPERATION The AD5251/AD5252 are dual-channel digital potentiometers in 1 kΩ, 10 kΩ, 50 kΩ, or 100 kΩ that allow 64/256 linear resistance step adjustments. The AD5251/AD5252 employ double-gate CMOS EEPROM technology, which allows resistance settings and user-defined data ...

  • Page 22

    AD5251/AD5252 DIGITAL INPUT/OUTPUT CONFIGURATION SDA is a digital input/output with an open-drain MOSFET that requires a pull-up resistor for proper communication. On the other hand, SCL and WP are digital inputs for which pull-up resistors are recommended to minimize the ...

  • Page 23

    LAYOUT AND POWER SUPPLY BIASING It is always a good practice to employ a compact, minimum lead-length layout design. The leads to the input should be as direct as possible, with a minimum conductor length. Ground paths should have low ...

  • Page 24

    AD5251/AD5252 100 (Code in Decimal) Figure 42. AD5251 R (D) and R (D) vs. Decimal Code WA WB Since the digital potentiometer is not ideal Ω finite wiper ...

  • Page 25

    APPLICATIONS INFORMATION LCD PANEL V ADJUSTMENT COM Large LCD panels usually require an adjustable V centered around with ±1 V swing and small steps adjustment. This example represents common DAC appli- cations where the window ...

  • Page 26

    AD5251/AD5252 OUTLINE DIMENSIONS 4.50 4.40 4.30 PIN 1 1.05 1.00 0.80 0.15 0.05 COPLANARITY 0.10 5.10 5.00 4. 6.40 BSC 1 7 0.65 BSC 1.20 0.20 MAX 0.09 8° SEATING 0° 0.30 PLANE 0.19 COMPLIANT TO JEDEC STANDARDS ...

  • Page 27

    ... AD5252BRUZ100-RL7 256 2 EVAL-AD5252EBZ 256 1 In the package marking, Line 1 shows the part number. Line 2 shows the branding information, such that kΩ, B10 = 10 kΩ, and so on. There is also a “#” marking for the Pb-free part. Line 3 shows the date code in YYWW. ...

  • Page 28

    AD5251/AD5252 NOTES 2 Purchase of licensed I C components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I Rights to use these components system, ...