Single/Dual, +15 V/5 V, 256-Position, 2 I C-Compatible Digital Potentiometer AD5280/AD5282 logic outputs that enable users to drive digital loads, logic gates, FEATURES LED drivers, and analog switches in their system. AD5280: 1 channel AD5282: 2 channels The AD5280/AD5282 are available in thin, surface-mounted 256 positions 14-lead TSSOP and 16-lead TSSOP. All parts are guaranteed to +10 V to +15 V single supply 5.5 V dual-supply operation operate over the extended industrial temperature range of Fixed terminal resistance: 20 k, 50 k, 200 k 40C to +85C. For 3-wire SPI-compatible interface applica- Low temperature coefficient: 30 ppm/C tions, see the AD5260/AD5262 product information on 1 Power-on midscale preset www.analog.com. Programmable reset FUNCTIONAL BLOCK DIAGRAMS o o Operating temperature: 40 C to +85 C A WB O O 1 2 2 I C-compatible interface APPLICATIONS SHDN Multimedia, video, and audio V DD V Communications L RDAC REGISTER OUTPUT REGISTER V SS Mechanical potentiometer replacement Instrumentation: gain, offset adjustment ADDRESS PWR ON Programmable voltage source CODE RESET 8 Programmable current source SCL Line impedance matching SERIAL INPUT REGISTER SDA GENERAL DESCRIPTION GND AD5280 The AD5280/AD5282 are single-channel and dual-channel, 2 AD0 AD1 256-position, digitally controlled variable resistors (VRs) . Figure 1. AD5280 The devices perform the same electronic adjustment function A W B A W B O as a potentiometer, trimmer, or variable resistor. Each VR offers 1 1 1 2 2 2 1 a completely programmable value of resistance between the OUTPUT A terminal and the wiper or the B terminal and the wiper. The SHDN REGISTER fixed A-to-B terminal resistance of 20 k, 50 k, or 200 k has VV DDDD a 1% channel-to-channel matching tolerance. The nominal V L RDAC1 REGISTER RDAC2 REGISTER V SS temperature coefficient of both parts is 30 parts per million/ degrees centigrade (ppm/C). Another key feature is that the ADDRESS parts can operate up to +15 V or 5 V. PWR ON CODE 8 RESET Wiper position programming defaults to midscale at system SCL power-on. When powered, the VR wiper position is programmed SERIAL INPUT REGISTER SDA 2 by an I C-compatible, 2-wire serial data interface. The AD5280/ GND AD5282 AD5282 feature sleep mode programmability. This allows any level of preset in power-up and is an alternative to a costly AD0 AD1 EEPROM solution. Both parts have additional programmable Figure 2. AD5282 1 Assert shutdown and program the device during power-up, then deassert the shutdown to achieve the desired preset level. 2 The terms digital potentiometer, VR, and RDAC are used interchangeably. Rev. C 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 20022009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 02929-070 02929-001AD5280/AD5282 TABLE OF CONTENTS Features .............................................................................................. 1 Multiple Devices on One Bus ................................................... 17 Applications ....................................................................................... 1 Level Shift for Bidirectional Interface ...................................... 18 General Description ......................................................................... 1 Level Shift for Negative Voltage Operation ............................ 18 Functional Block Diagrams ............................................................. 1 ESD Protection ........................................................................... 18 Revision History ............................................................................... 2 Terminal Voltage Operating Range ......................................... 18 Specif icat ions ..................................................................................... 3 Power-Up Sequence ................................................................... 18 Electrical Characteristics ............................................................. 3 Layout and Power Supply Bypassing ....................................... 19 Absolute Maximum Ratings ............................................................ 5 Applications Information .............................................................. 20 Thermal Resistance ...................................................................... 5 Bipolar DC or AC Operation from Dual Supplies ................. 20 ESD Caution .................................................................................. 5 Gain Control Compensation .................................................... 20 2 Pin Configurations and Function Descriptions ........................... 6 15 V, 8-Bit I C DAC .................................................................... 20 Typical Performance Characteristics ............................................. 7 8-Bit Bipolar DAC ...................................................................... 21 Test Circuits ..................................................................................... 12 Bipolar Programmable Gain Amplifier ................................... 21 Theory of Operation ...................................................................... 14 Programmable Voltage Source with Boosted Output ........... 21 Rheostat Operation .................................................................... 14 Programmable Current Source ................................................ 22 Potentiometer Operation........................................................... 14 Programmable Bidirectional Current Source ......................... 22 Digital Interface .............................................................................. 16 Programmable Low-Pass Filter ................................................ 23 2-Wire Serial Bus ........................................................................ 16 Programmable Oscillator .......................................................... 23 Readback RDAC Value .............................................................. 17 RDAC Circuit Simulation Model ............................................. 24 Additional Programmable Logic Output ................................ 17 Macro Model Net List for RDAC ............................................. 24 Self-Contained Shutdown Function and Programmable Outline Dimensions ....................................................................... 25 Preset ............................................................................................ 17 Ordering Guide .......................................................................... 26 REVISION HISTORY 7/09Rev. B to Rev. C Changes to Features Section............................................................ 1 Updated Outline Dimensions, RU-14 ......................................... 25 Changes to Ordering Guide .......................................................... 26 8/07Rev. A to Rev. B Updated Operating Temperature Range Throughout ................... 1 Changes to the Features Section ....................................................... 1 Changes to the General Description Section .................................. 1 Changes to Table 2 .............................................................................. 3 Added the Thermal Resistance Section ........................................... 5 Changes to the Ordering Guide ...................................................... 26 11/05Rev. 0 to Rev. A Updated Format ................................................................... Universal Updated Outline Dimensions ......................................................... 26 Changes to Ordering Guide ............................................................ 27 10/02Revision 0: Initial Version Rev. C Page 2 of 28