AD5228Data SheetPIN CONFIGURATION AND FUNCTION DESCRIPTIONSPU18VDDPD27PREAD5228A36BGND45W 04422-0-003 Figure 6. SOT-23-8 Pin Configuration Table 4. Pin Function Descriptions Pin No.MnemonicDescription 1 PU Push-Up Pin. Connect to the external pushbutton. Active low. A 100 kΩ pull-up resistor is connected to VDD. 2 PD Push-Down Pin. Connect to the external pushbutton. Active low. A 100 kΩ pull-up resistor is connected to VDD. 3 A Resistor Terminal A. GND ≤VA ≤ VDD. 4 GND Common Ground. 5 W Wiper Terminal W. GND ≤ VW ≤ VDD. 6 B Resistor Terminal B. GND ≤ VB ≤ VDD. 7 PRE Power-On Preset. Output = midscale if PRE = GND; output = zero scale if PRE = VDD. Do not let the PRE pin float. No pull-up resistor is needed. 8 VDD Positive Power Supply, 2.7 V to 5.5 V. Rev. B | Page 6 of 18 Document Outline FEATURES APPLICATIONS 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 CONTROLLING INPUTS TERMINAL VOLTAGE OPERATION RANGE POWER-UP AND POWER-DOWN SEQUENCES LAYOUT AND POWER SUPPLY BIASING APPLICATIONS MANUAL ADJUSTABLE LED DRIVER ADJUSTABLE CURRENT SOURCE FOR LED DRIVER ADJUSTABLE HIGH POWER LED DRIVER AUTOMATIC LCD PANEL BACKLIGHT CONTROL AUDIO AMPLIFIER WITH VOLUME CONTROL CONSTANT BIAS WITH SUPPLY TO RETAIN RESISTANCE SETTING OUTLINE DIMENSIONS ORDERING GUIDE