link to page 3 link to page 4 link to page 5 link to page 5 link to page 6 link to page 7 link to page 10 link to page 10 link to page 11 link to page 11 link to page 11 link to page 11 link to page 12 link to page 12 link to page 12 link to page 12 link to page 12 link to page 13 link to page 13 link to page 13 link to page 14 link to page 15 link to page 15 AD5227TABLE OF CONTENTS Electrical Characteristics ... 3 Applications ... 12 Interface Timing Diagrams ... 4 Manual Control with Toggle and Pushbutton Switches .. 12 Absolute Maximum Ratings .. 5 Manual Control with Rotary Encoder ... 12 ESD Caution .. 5 Adjustable LED Driver .. 12 Pin Configuration and Function Descriptions ... 6 Adjustable Current Source for LED Driver .. 12 Typical Performance Characteristics ... 7 Adjustable High Power LED Driver .. 13 Theory of Operation .. 10 Automatic LCD Panel Backlight Control .. 13 Programming the Digital Potentiometers ... 10 6-Bit Controller .. 13 Digital Interface .. 11 Constant Bias with Supply to Retain Resistance Setting ... 14 Terminal Voltage Operation Range ... 11 Outline Dimensions ... 15 Power-Up and Power-Down Sequences .. 11 Ordering Guide .. 15 Layout and Power Supply Biasing .. 11 REVISION HISTORY5/09—Rev. A to Rev. B Changes to Table 2……………………………………………3 4/09—Rev. 0 to Rev. A Changes to Table 2……………………………………………3 Changes to Ordering Guide …………………………………15 3/04—Revision 0: Initial Version Rev. B | Page 2 of 16 Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY ELECTRICAL CHARACTERISTICS INTERFACE TIMING DIAGRAMS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION PROGRAMMING THE DIGITAL POTENTIOMETERS Rheostat Operation Potentiometer Mode Operation DIGITAL INTERFACE TERMINAL VOLTAGE OPERATION RANGE POWER-UP AND POWER-DOWN SEQUENCES LAYOUT AND POWER SUPPLY BIASING APPLICATIONS MANUAL CONTROL WITH TOGGLE AND PUSHBUTTON SWITCHES MANUAL CONTROL WITH ROTARY ENCODER ADJUSTABLE LED DRIVER ADJUSTABLE CURRENT SOURCE FOR LED DRIVER ADJUSTABLE HIGH POWER LED DRIVER AUTOMATIC LCD PANEL BACKLIGHT CONTROL 6-BIT CONTROLLER CONSTANT BIAS WITH SUPPLY TO RETAIN RESISTANCE SETTING OUTLINE DIMENSIONS ORDERING GUIDE