link to page 1 link to page 1 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 8 link to page 9 link to page 12 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 16 link to page 16 link to page 16 link to page 17 link to page 18 link to page 19 link to page 20 link to page 21 link to page 22 link to page 23 link to page 24 link to page 24 link to page 24 link to page 25 link to page 25 AD7946Data SheetTABLE OF CONTENTS Features .. 1 Voltage Reference Input .. 14 Applications ... 1 Power Supply ... 15 Typical Application Circuit ... 1 Supplying the ADC from the Reference .. 15 General Description ... 1 Single-Supply Application ... 15 Revision History ... 2 Digital Interface .. 16 Specifications ... 3 CS MODE 3-Wire, No BUSY Indicator .. 17 Timing Specifications .. 5 CS Mode 3-Wire with BUSY Indicator ... 18 Absolute Maximum Ratings .. 6 CS Mode 4-Wire, No BUSY Indicator ... 19 ESD Caution .. 6 CS Mode 4-Wire with BUSY Indicator ... 20 Pin Configurations and Function Descriptions ... 7 Chain Mode, No BUSY Indicator .. 21 Typical Performance Characteristics ... 8 Chain Mode with BUSY Indicator ... 22 Terminology .. 11 Application Guidelines .. 23 Theory of Operation .. 12 Layout .. 23 Circuit Information .. 12 Evaluating the Performance of the AD7946 .. 23 Converter Operation .. 12 Outline Dimensions ... 24 Typical Connection Diagram.. 13 Ordering Guide .. 24 Analog Input ... 13 Driver Amplifier Choice .. 14 REVISION HISTORY 7/14—Rev. A to Rev. B12/07—Rev. 0 to Rev. A Replaced QFN with LFCSP .. Throughout QFN Package Available .. Universal Changed Application Diagram Section to Typical Application Changes to Table 1 ... 1 Circuit Section .. 1 Changes to Table 5 ... 6 Changes to Product Title and Features Section .. 1 Changes to Ordering Guide .. 24 Added Note 1, General Description Section ... 1 Added EPAD Notation to Figure 5 and Table 6.. 7 7/05—Revision 0: Initial Version Changes to Figure 25 .. 13 Changes to Evaluating the Performance of the AD7946 Section . 23 Updated Outline Dimensions ... 24 Changes to Ordering Guide .. 24 Rev. B | Page 2 of 24 Document Outline Features Applications Typical Application Circuit General Description Table of Contents Revision History Specifications Timing Specifications Absolute Maximum Ratings ESD Caution Pin Configurations and Function Descriptions Typical Performance Characteristics Terminology Theory of Operation Circuit Information Converter Operation Transfer Functions Typical Connection Diagram Analog Input Driver Amplifier Choice Voltage Reference Input Power Supply Supplying the ADC from the Reference Single-Supply Application Digital Interface CS/ MODE 3-Wire, No BUSY Indicator CS/ Mode 3-Wire with BUSY Indicator CS/ Mode 4-Wire, No BUSY Indicator CS/ Mode 4-Wire with BUSY Indicator Chain Mode, No BUSY Indicator Chain Mode with BUSY Indicator Application Guidelines Layout Evaluating the Performance of the AD7946 Outline Dimensions Ordering Guide