64-Position OTP Digital Potentiometer AD5171 FEATURES FUNCTIONAL BLOCK DIAGRAM 64 position SCL A One-time programmable (OTP) set-and-forget resistance 2 I C INTERFACE SDA AND settinglow cost alternative over EEMEM CONTROL LOGIC W Unlimited adjustments prior to OTP activation 5 k, 10 k, 50 k, 100 k end-to-end resistance AD0 Low temperature coefficient: 5 ppm/C in potentiometer mode B Low temperature coefficient: 35 ppm/C in rheostat mode Compact standard 8-lead SOT-23 package WIPER V DD REGISTER Low power: I = 10 A maximum DD GND Fast settling time: t = 5 s typical in power-up FUSE S LINK 2 I C-compatible digital interface AD5171 Computer software replaces microcontroller in factory Figure 1. programming applications Full read/write of wiper register W 1 8 A 2 Extra I C device address pin V 2 AD5171 7 B DD TOP VIEW Low operating voltage: 2.7 V to 5.5 V 6 GND 3 AD0 (Not to Scale) OTP validation check function SCL 4 5 SDA Automotive temperature range: 40C to +125C Figure 2. Pin Configuration When this permanent setting is achieved, the value does not APPLICATIONS change regardless of supply variations or environmental stresses System calibrations under normal operating conditions. To verify the success of Electronics level settings permanent programming, Analog Devices, Inc., patterned the Mechanical trimmers and potentiometer replacements OTP validation such that the fuse status can be discerned from Automotive electronics adjustments two validation bits in read mode. Gain control and offset adjustments For applications that program the AD5171 in factories, Analog Transducer circuit adjustments 1 Devices offers device programming software that operates Programmable filters up to 1.5 MHz BW across Windows 95 to XP platforms, including Windows NT. This software application effectively replaces the need for external GENERAL DESCRIPTION 2 I C controllers or host processors and, therefore, significantly The AD5171 is a 64-position, one-time programmable (OTP) reduces the development time of the users. 2 digital potentiometer that uses fuse link technology to achieve An AD5171 evaluation kit includes the software, connector, and the memory retention of the resistance setting function. OTP is cable that can be converted for factory programming applications. a cost-effective alternative over the EEMEM approach for users The AD5171 is available in a compact 8-lead SOT-23 package. who do not need to reprogram new memory settings in the All parts are guaranteed to operate over the automotive temper- digital potentiometer. This device performs the same electronic ature range of 40C to +125C. Besides its unique OTP feature, adjustment function as most mechanical trimmers and variable 2 the AD5171 lends itself well to other general-purpose digital resistors. The AD5171 is programmed using a 2-wire, I C- potentiometer applications due to its temperature performance, compatible digital control. It allows unlimited adjustments small form factor, and low cost. before permanently setting the resistance value. During the OTP activation, a permanent fuse blown command is sent after the final value is determined, freezing the wiper position at a given 1 setting (analogous to placing epoxy on a mechanical trimmer). Applies to 5 k parts only. 2 The terms digital potentiometer and RDAC are used interchangeably. Rev. D 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 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 20042008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 03437-002 03437-001AD5171 TABLE OF CONTENTS Features .............................................................................................. 1 Power-Up/Power-Down Sequences ......................................... 15 Applications ....................................................................................... 1 Controlling the AD5171 ................................................................ 16 General Description ......................................................................... 1 Software Programming ............................................................. 16 Functional Block Diagram .............................................................. 1 Device Programming ................................................................. 16 2 Revision History ............................................................................... 2 I C Controller Programming .................................................... 17 2 Specif icat ions ..................................................................................... 3 I C-Compatible 2-Wire Serial Bus ........................................... 17 Electrical Characteristics: 5 k, 10 k, 50 k, and 100 k .. 3 Controlling Two Devices on One Bus ..................................... 18 Timing Characteristics: 5 k, 10 k, 50 k, and 100 k ...... 5 Applications Information .............................................................. 19 Absolute Maximum Ratings ............................................................ 6 DAC .............................................................................................. 19 ESD Caution .................................................................................. 6 Gain Control Compensation .................................................... 19 Pin Configuration and Function Descriptions ............................. 7 Programmable Voltage Source with Boosted Output ........... 19 Typical Performance Characteristics ............................................. 8 Level Shifting for Different Voltage Operation ...................... 19 Theory of Operation ...................................................................... 12 Resistance Scaling ...................................................................... 19 One-Time Programming (OTP) .............................................. 12 Resolution Enhancement .......................................................... 20 Variable Resistance and Voltage for Rheostat Mode ............. 13 RDAC Circuit Simulation Model ............................................. 20 Variable Resistance and Voltage for Potentiometer Mode .... 13 Evaluation Board ............................................................................ 21 Power Supply Considerations ................................................... 14 Outline Dimensions ....................................................................... 22 ESD Protection ........................................................................... 14 Ordering Guide .......................................................................... 22 Terminal Voltage Operating Range .......................................... 15 REVISION HISTORY 7/08Rev. C to Rev. D Changes to Power Supplies Parameter in Table 1.........................3 1/05Rev. A to Rev. B Updated Fuse Blow Condition to 400 ms Throughout ...............5 Change to Features ............................................................................ 1 Changes to Electrical Characteristics ............................................. 3 1/08Rev. B to Rev. C Change to Table 3 .............................................................................. 6 Updated Format .................................................................. Universal Changes to Power Supply Considerations Section .................... 13 Deleted Note 1 Renumbered Sequentially ................................... 1 Changes to Level Shifting for Different Voltage Operation Changes to Table 1 ............................................................................ 3 S ection .............................................................................................. 19 Changes to Table 2 ............................................................................ 5 Added Note to Ordering Guide .................................................... 22 Changes to Table 3 ............................................................................ 6 Changes to Table 4 ............................................................................ 7 11/04Rev. 0 to Rev. A Changes to Figure 13 to Figure 16 .................................................. 9 Changes to Specifications ................................................................. 3 Changes to Figure 17 and Figure 18 ............................................. 10 Changes to Table 3 ............................................................................. 7 Inserted Figure 24 ........................................................................... 11 Changes to One-Time Programming Section ............................ 11 Changes to One-Time Programming (OTP) Section and Power Changes to Power Supply Consideration Section ...................... 11 Supply Considerations Section ..................................................... 12 Changes to Figure 26 and Figure 27............................................. 12 Deleted Figure 25 and Figure 26 ................................................... 13 1/04Revision 0: Initial Version Updated Outline Dimensions ....................................................... 22 Changes to Ordering Guide .......................................................... 22 Rev. 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