256-Position, Ultralow Power 1.8 V Logic-Level Digital Potentiometer AD5165 FEATURES FUNCTIONAL BLOCK DIAGRAM Ultralow standby power IDD = 50 nA typical V DD 256-position End-to-end resistance 100 k A CS 3-WIRE Logic high voltage 1.8 V INTERFACE SDI Power supply 2.7 V to 5.5 V W CLK Low temperature coefficient 35 ppm/C Compact thin 8-lead TSOT-8 (2.9 mm 2.8 mm) package WIPER B Simple 3-wire digital interface REGISTER Wide operating temperature 40C to +125C Pin-to-pin compatible to AD5160 with CS inverted GND APPLICATIONS Figure 1. Battery-operated electronics adjustment Remote utilities meter adjustment Mechanical potentiometer replacement PIN CONFIGURATION Transducer circuit adjustment Automotive electronics adjustment W 1 8 A Gain control and offset adjustment V 2 AD5165 7 B DD TOP VIEW 3 6 CS GND System calibration (Not to Scale) CLK 4 5 SDI VCXO adjustment Figure 2. GENERAL OVERVIEW The AD5165 provides a compact 2.9 mm 2.8 mm packaged solution for 256-position adjustment applications. These devices TYPICAL APPLICATION perform the same electronic adjustment function as mechanical potentiometers or variable resistors, with enhanced resolution, 5V V = 1.8V MIN OH solid-state reliability, and superior low temperature coefficient performance. The AD5165s supply voltage requirement is 2.7 V V DD 3.3V to 5.5 V, but its logic voltage requirement is 1.8 V to V . The V DD A AD5165 WIDE TERMINAL AD5165 consumes very low quiescent power during standby V W VOLTAGE RANGE: DIGITAL mode and is ideal for battery-operated applications. CS CONTROL V B 0V < V ,V ,V < 5V CLK A B W LOGIC OR Wiper settings are controlled through a simple 3-wire interface. SDI GND MICRO The interface is similar to the SPI digital interface except for the inverted chip-select function that minimizes logic power con- sumption in the idling state. The resistance between the wiper Figure 3. and either endpoint of the fixed resistor varies linearly with respect to the digital code transferred into the wiper register. Note: Operating from a 2.7 V to 5.5 V power supply and consuming The terms digital potentiometer, RDAC, and VR are used interchangeably. less than 50 nA typical standby power allows use in battery- operated portable or remote utility device applications. Rev. 0 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. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Specifications subject to change without notice. No license is granted by implication Tel: 781.329.4700 www.analog.com or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Fax: 781.326.8703 2004 Analog Devices, Inc. All rights reserved. 04749-0-002 04749-0-001 04749-0-003AD5165 TABLE OF CONTENTS 3-Wire Serial Bus Digital Interface .......................................... 14 Electrical Characteristics100 k Version .................................. 3 ESD Protection ........................................................................... 14 Absolute Maximum Ratings............................................................ 5 Terminal Voltage Operating Range.......................................... 14 Pin Configuration and Functional Descriptions.......................... 6 Power-Up Sequence ................................................................... 14 Typical Performance Characteristics ............................................. 7 Layout and Power Supply Bypassing ....................................... 15 Test Circuits..................................................................................... 11 Evaluation Board........................................................................ 15 3-Wire Digital Interface................................................................. 12 Outline Dimensions ....................................................................... 16 Theory of Operation ...................................................................... 13 Ordering Guide .......................................................................... 16 Programming the Variable Resistor ......................................... 13 Programming the Potentiometer Divider ............................... 14 REVISION HISTORY 4/04Revision 0: Initial Version Rev. 0 Page 2 of 16