2 Dual 64-/256-Position I C Nonvolatile Memory Digital Potentiometers Data Sheet AD5251/AD5252 FEATURES FUNCTIONAL BLOCK DIAGRAM AD5251: Dual 64-position resolution V RDAC EEMEM RDAC1 DD A1 RDAC1 AD5252: Dual 256-position resolution EEMEM RAB V SS REGIS- W1 POWER-ON TOL TER DGND AD5251: 50 k REFRESH B1 WP AD5252: 1 k , 10 k , 50 k , 100 k DATA RDAC3 1 A3 SCL Nonvolatile memory stores wiper setting w/write protection RDAC3 2 SDA I C REGIS- W3 Power-on refreshed with EEMEM settings in 300 s typ SERIAL TER CONTROL B3 INTERFACE EEMEM rewrite time = 540 s typ AD0 COMMAND DECODE LOGIC AD1 Resistance tolerance stored in nonvolatile memory ADDRESS 12 extra bytes in EEMEM for user-defined information DECODE LOGIC AD5251/ POWER- 2 I C-compatible serial interface AD5252 ON RESET CONTROL LOGIC 2 Direct read/write access of RDAC and EEMEM registers Predefined linear increment/decrement commands Figure 1. Predefined 6 dB step change commands and extra EEMEM for storing user-defined information, such as Synchronous or asynchronous dual-channel update memory data for other components, look-up table, or system Wiper setting readback 4 MHz bandwidth1 k version identification information. Single supply 2.7 V to 5.5 V 2 The AD5251/AD5252 allow the host I C controllers to write Dual supply 2.25 V to 2.75 V any of the 64-/256-step wiper settings in the RDAC registers 2 slave address decoding bits allow operation of 4 devices and store them in the EEMEM. Once the settings are stored, 100-year typical data retention, T = 55C A they are restored automatically to the RDAC registers at system Operating temperature: 40C to +105C power-on the settings can also be restored dynamically. APPLICATIONS The AD5251/AD5252 provide additional increment, decrement, +6 dB step change, and 6 dB step change in Mechanical potentiometer replacement synchronous or asynchronous channel update mode. The General-purpose DAC replacement increment and decrement functions allow stepwise linear LCD panel VCOM adjustment adjustments, with a 6 dB step change equivalent to doubling White LED brightness adjustment or halving the RDAC wiper setting. These functions are useful RF base station power amp bias control for steep-slope, nonlinear adjustments, such as white LED Programmable gain and offset control brightness and audio volume control. Programmable voltage-to-current conversion Programmable power supply The AD5251/AD5252 have a patented resistance-tolerance Sensor calibrations storing function that allows the user to access the EEMEM and obtain the absolute end-to-end resistance values of the RDACs GENERAL DESCRIPTION for precision applications. 2 The AD5251/AD5252 are dual-channel, I C, nonvolatile mem- The AD5251/AD5252 are available in TSSOP-14 packages. ory, digitally controlled potentiometers with 64/256 positions, AD5251 has only 50 k resistance options and AD5252 is respectively. These devices perform the same electronic adjust- available in 1 k, 10 k, 50 k, and 100 k options. All parts ment functions as mechanical potentiometers, trimmers, and are guaranteed to operate over the 40C to +105C extended variable resistors. The parts versatile programmability allows industrial temperature range. 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, 1 The terms nonvolatile memory and EEMEM are used interchangeably. 2 The terms digital potentiometer and RDAC are used interchangeably. Rev. E Document Feedback 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20042017 Analog Devices, Inc. All rights reserved. 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. Technical Support www.analog.com 03823-0-001AD5251/AD5252 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Theory of Operation ...................................................................... 21 Applications ....................................................................................... 1 Linear Increment/Decrement Commands ............................. 21 General Description ......................................................................... 1 6 dB Adjustments (Doubling/Halving Wiper Setting) ....... 21 Functional Block Diagram .............................................................. 1 Digital Input/Output Configuration........................................ 21 Revision History ............................................................................... 2 Multiple Devices on One Bus ................................................... 22 Electrical Characteristics ................................................................. 3 Terminal Voltage Operation Range ......................................... 22 1 k Version .................................................................................. 3 Power-Up and Power-Down Sequences .................................. 22 10 k, 50 k, 100 k Versions .................................................. 5 Layout and Power Supply Biasing ............................................ 23 Interface Timing Characteristics ................................................ 7 Digital Potentiometer Operation ............................................. 23 Absolute Maximum Ratings ............................................................ 8 Programmable Rheostat Operation ......................................... 23 ESD Caution .................................................................................. 8 Programmable Potentiometer Operation ............................... 24 Pin Configuration and Function Descriptions ............................. 9 Applications Information .............................................................. 25 Typical Performance Characteristics ........................................... 10 LCD Panel V Adjustment .................................................... 25 COM 2 I C Interface ..................................................................................... 14 Current-Sensing Amplifier ....................................................... 25 2 I C Interface General Description ............................................ 14 Adjustable High Power LED Driver ........................................ 25 2 I C Interface Detail Description ............................................... 15 Outline Dimensions ....................................................................... 26 2 I C-Compatible 2-Wire Serial Bus ........................................... 20 Ordering Guide .......................................................................... 27 REVISION HISTORY 11/2017Rev. D to Rev. E 9/2005Rev. 0 to Rev. A Changes to Features Section and General Description Section ........ 1 Updated Format .................................................................. Universal Changes to Theory of Operation Section .................................... 21 Change to Figure 6 ......................................................................... 10 Changes to Ordering Guide .......................................................... 27 Changes to Figure 28 ...................................................................... 15 Changes to Figure 29 ...................................................................... 17 9/2012Rev. C to Rev. D Changes to RDAC/EEMEM Quick Commands Section .......... 18 Changed Temperature Range from 40C to +85C to 40C to Changes to EEMEM Write Protection Section .......................... 18 +105C (Throughout) ...................................................................... 1 Changes to Figure 37 ...................................................................... 22 EE Changed AA Leakage Current from 5 A to 8 A, Table 1 ........ 4 WP Deleted Table 13 and Table 14 ...................................................... 23 EE Change to Figure 42 ....................................................................... 24 Changed AA AA Leakage Current from 5 A to 8 A, Table 2 ........ 5 WP Change to Figure 46 ....................................................................... 25 Changes to Figure 11 and Figure 12 ............................................. 11 Changes to Ordering Guide .......................................................... 27 12/2011Rev. B to Rev. C 6/2004Revision 0: Initial Version Changes to Theory of Operation Section .................................... 21 Changes to Ordering Guide .......................................................... 27 10/2009Rev. A to Rev. B Changes to Figure 15 ...................................................................... 12 Changes to Figure 27 ...................................................................... 15 Rev. E Page 2 of 28