link to page 1 link to page 1 link to page 3 link to page 4 link to page 6 link to page 7 link to page 7 link to page 7 link to page 8 link to page 9 link to page 11 link to page 12 link to page 12 link to page 13 link to page 13 link to page 13 link to page 13 link to page 14 link to page 14 link to page 15 link to page 15 link to page 15 link to page 16 link to page 17 link to page 1 link to page 1 link to page 13 link to page 15 link to page 17 link to page 13 AD7780TABLE OF CONTENTS Features .. 1 Power-Down/Reset (PDRST) ... 12 Applications ... 1 Analog Input Channel ... 12 Functional Block Diagram .. 1 Bipolar Configuration .. 12 General Description ... 1 Data Output Coding .. 12 Revision History ... 2 Reference ... 12 Specifications ... 3 Bridge Power-Down Switch .. 13 Timing Characteristics .. 5 Digital Interface .. 13 Absolute Maximum Ratings .. 6 Applications Information .. 14 Thermal Resistance .. 6 Weigh Scales .. 14 ESD Caution .. 6 Performance in a Weigh Scale System ... 14 Pin Configurations and Function Descriptions ... 7 EMI Recommendations ... 14 Typical Performance Characteristics ... 8 Grounding and Layout .. 15 Output Noise and Resolution.. 10 Outline Dimensions ... 16 Theory of Operation .. 11 Ordering Guide .. 16 Filter, Data Rate, and Settling Time ... 11 Gain .. 12 REVISION HISTORY9/09—Rev. 0 to Rev. A Changes to Specifications Table .. 3 4/09—Revision 0: Initial Version Rev. A | Page 2 of 16 Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING CHARACTERISTICS Circuit and Timing Diagrams ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS OUTPUT NOISE AND RESOLUTION THEORY OF OPERATION FILTER, DATA RATE, AND SETTLING TIME GAIN POWER-DOWN/RESET () ANALOG INPUT CHANNEL BIPOLAR CONFIGURATION DATA OUTPUT CODING REFERENCE BRIDGE POWER-DOWN SWITCH DIGITAL INTERFACE APPLICATIONS INFORMATION WEIGH SCALES PERFORMANCE IN A WEIGH SCALE SYSTEM EMI RECOMMENDATIONS GROUNDING AND LAYOUT OUTLINE DIMENSIONS ORDERING GUIDE