EVAL-AD5254EBZ

Manufacturer Part NumberEVAL-AD5254EBZ
DescriptionEvaluation Board
ManufacturerAnalog Devices Inc
EVAL-AD5254EBZ datasheet
 


Specifications of EVAL-AD5254EBZ

Main PurposeDigital PotentiometerUtilized Ic / PartAD5245
Lead Free Status / RoHS StatusLead free / RoHS CompliantSecondary Attributes-
Embedded-Primary Attributes-
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FEATURES
AD5253: quad 64-position resolution
AD5254: quad 256-position resolution
1 kΩ, 10 kΩ, 50 kΩ, 100 kΩ
1
Nonvolatile memory
stores wiper settings w/write protection
Power-on refreshed to 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
I
2
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 quad-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
Low resolution DAC replacement
RGB LED backlight control
White LED brightness adjustment
RF base station power amp bias control
Programmable gain and offset control
Programmable attenuators
Programmable voltage-to-current conversion
Programmable power supply
Programmable filters
Sensor calibrations
GENERAL DESCRIPTION
The AD5253/AD5254 are quad-channel, I
mem-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.
Quad 64-/256-Position I
Memory Digital Potentiometers
V
DD
V
SS
DGND
WP
SCL
SDA
AD0
AD1
The AD5253/AD5254 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 AD5253/AD5254 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 AD5253/AD5254 have a patented resistance-tolerance
storing function that allows the user to access the EEMEM and
2
C®, nonvolatile
obtain the absolute end-to-end resistance values of the RDACs
for precision applications.
The AD5253/AD5254 are available in TSSOP-20 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 © 2003–2009 Analog Devices, Inc. All rights reserved.
2
C Nonvolatile
AD5253/AD5254
FUNCTIONAL BLOCK DIAGRAM
RDAC EEMEM
RDAC0
EEMEM
REGIS-
R
TOL
POWER-ON
AB
TER
REFRESH
DATA
RDAC1
2
I
C
REGIS-
SERIAL
TER
CONTROL
INTERFACE
COMMAND
DECODE LOGIC
RDAC2
ADDRESS
REGIS-
DECODE LOGIC
TER
CONTROL LOGIC
RDAC3
REGIS-
TER
AD5253/AD5254
Figure 1.
2
C controllers to write
www.analog.com
RDAC0
A0
W0
B0
RDAC1
A1
W1
B1
RDAC2
A2
W2
B2
RDAC3
A3
W3
B3

EVAL-AD5254EBZ Summary of contents

  • Page 1

    FEATURES AD5253: quad 64-position resolution AD5254: quad 256-position resolution 1 kΩ, 10 kΩ, 50 kΩ, 100 kΩ 1 Nonvolatile memory stores wiper settings w/write protection Power-on refreshed to EEMEM settings in 300 μs typ EEMEM rewrite time = 540 μs ...

  • Page 2

    AD5253/AD5254 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 Symbol DC CHARACTERISTICS— RHEOSTAT MODE Resolution N Resistor Differential Nonlinearity 2 R-DNL 2 ...

  • Page 4

    AD5253/AD5254 Parameter Symbol DIGITAL INPUTS AND OUTPUTS Input Logic High V Input Logic Low V Output Logic High (SDA) V Output Logic Low (SDA Leakage Current I A0 Leakage Current I Input Leakage Current I (Other than WP ...

  • Page 5

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

  • Page 6

    AD5253/AD5254 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. 1 Parameter INTERFACE TIMING SCL Clock Frequency t Bus-Free Time Between Stop and Start BUF t Hold Time (Repeated Start) HD;STA ...

  • Page 8

    AD5253/AD5254 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 W0 Wiper Terminal of RDAC0 Terminal of RDAC0 Terminal of RDAC0 AD0 I C ...

  • Page 10

    AD5253/AD5254 TYPICAL PERFORMANCE CHARACTERISTICS 1.0 0 –40°C, +25°C, +85°C, +125°C 0.6 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

    AD5253/AD5254 0 –6 0x80 –12 0x40 –18 0x20 –24 0x10 –30 0x08 –36 0x04 –42 0x02 –48 0x01 –54 –60 10 100 1k 10k 100k FREQUENCY (Hz) Figure 15. Gain vs. Frequency vs. Code 0x80 –6 0x40 –12 ...

  • Page 13

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

  • Page 14

    AD5253/AD5254 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) 2 AD1, AD0 = I C device ...

  • Page 16

    AD5253/AD5254 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

    From Master to Slave From Slave to Master S = start condition P = stop condition A = acknowledge (SDA low not acknowledge (SDA high) 2 AD1, AD0 = I C device address bits, must match with the ...

  • Page 18

    AD5253/AD5254 RDAC/EEMEM Quick Commands The AD5253/AD5254 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

    AD5253/AD5254 2 I C-COMPATIBLE 2-WIRE SERIAL BUS 1 SCL AD1 AD0 R SDA START BY FRAME 1 MASTER SLAVE ADDRESS BYTE 1 SCL 0 SDA START BY MASTER The first byte of the AD5253/AD5254 is ...

  • Page 21

    THEORY OF OPERATION The AD5253/AD5254 are quad-channel digital potentiometers in 1 kΩ, 10 kΩ, 50 kΩ, or 100 kΩ that allow 64/256 linear resis- tance step adjustments. The AD5253/AD5254 employ double- gate CMOS EEPROM technology, which allows resistance settings and ...

  • Page 22

    AD5253/AD5254 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

    × 4 DECODER × 4 DECODER 4 2 × 4 DECODER × 4 DECODER P4 R4 Figure 38. Four Devices with AD1 and AD0 of ...

  • Page 24

    AD5253/AD5254 DIGITAL POTENTIOMETER OPERATION The structure of the RDAC is designed to emulate the performance of a mechanical potentiometer. The RDAC contains a string of resistor segments with an array of analog switches that act as the wiper connection to ...

  • Page 25

    (Code in Decimal) Figure 43. AD5253 R (D) and R (D) vs. Decimal Code WA WB Since the digital potentiometer is not ideal Ω finite wiper resistance ...

  • Page 26

    AD5253/AD5254 APPLICATIONS INFORMATION RGB LED BACKLIGHT CONTROLLER FOR LCD PANELS Because high power (>1 W) RGB LEDs offer superior color quality compared with cold cathode florescent lamps (CCFLs) as backlighting sources likely that high-end LCD panels will employ ...

  • Page 27

    C10 10μ RDAC3 0.1μF 22kΩ 22kΩ B3 10kΩ SCL CLK U3D SDA SDI V = 2.5V REF AD8594 AD5254 250kΩ 250kΩ 250kΩ A2 RDAC2 B2 10kΩ A1 RDAC1 B1 ...

  • Page 28

    AD5253/AD5254 OUTLINE DIMENSIONS COPLANARITY 6.60 6.50 6. 4.50 4.40 4.30 6.40 BSC 1 10 PIN 1 0.65 BSC 1.20 MAX 0.15 0.20 0.05 0.09 0.30 0.19 SEATING 0.10 PLANE COMPLIANT TO JEDEC STANDARDS MO-153-AC Figure 46. 20-Lead Thin ...

  • Page 29

    ... AD5254BRUZ100-RL7 2 256 2 EVAL-AD5254EBZ 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 30

    AD5253/AD5254 NOTES Rev Page ...

  • Page 31

    NOTES Rev Page AD5253/AD5254 ...

  • Page 32

    AD5253/AD5254 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, ...