link to page 1 link to page 1 link to page 1 link to page 1 link to page 1 link to page 2 link to page 3 link to page 3 link to page 5 link to page 7 link to page 9 link to page 10 link to page 10 link to page 10 link to page 11 link to page 14 link to page 18 link to page 20 link to page 20 link to page 21 link to page 21 link to page 21 link to page 22 link to page 22 link to page 24 link to page 25 link to page 25 link to page 25 link to page 27 link to page 29 link to page 29 link to page 29 link to page 30 link to page 30 AD7656-1/AD7657-1/AD7658-1Data SheetTABLE OF CONTENTS Features .. 1 Theory of Operation .. 20 Applications ... 1 Converter Details ... 20 Functional Block Diagram .. 1 ADC Transfer Function ... 21 General Description ... 1 Internal/External Reference .. 21 Product Highlights ... 1 Typical Connection Diagram ... 21 Revision History ... 2 Driving the Analog Inputs .. 22 Specifications ... 3 Interface Options .. 22 AD7656-1 .. 3 Software Selection of ADCs .. 24 AD7657-1 .. 5 Changing the Analog Input Range (H/S SEL = 0) .. 25 AD7658-1 .. 7 Changing the Analog Input Range (H/S SEL = 1) .. 25 Timing Specifications .. 9 Serial Read Operation .. 25 Absolute Maximum Ratings .. 10 Daisy-Chain Mode (DCEN = 1, SER/PAR SEL = 1) ... 27 Thermal Resistance .. 10 Application Hints ... 29 ESD Caution .. 10 Layout .. 29 Pin Configuration and Function Descriptions ... 11 Power Supply Configuration... 29 Typical Performance Characteristics ... 14 Outline Dimensions ... 30 Terminology .. 18 Ordering Guide .. 30 REVISION HISTORY 3/12—Rev. C to Rev. D Changes to Table 3 ... 7 Changes to Figure 28 .. 22 Changes to Table 4 ... 9 Changes to Absolute Maximum Ratings Table .. 10 11/10—Rev. B to Rev. C Changes to Pin Functions Description Table ... 11 Added Power Supply Configuration Section .. 29 Changes to Figure 9 .. 14 Added Figure 39 .. 29 Changes to Converter Details Section ... 20 Changes to Internal/External Reference Section ... 21 6/10—Rev. A to Rev. B Changes to Interface Options Section ... 22 Changes to DC Accuracy Parameter, Table 1 ... 3 Changes to Parallel Interface Section .. 22 Changes to DC Accuracy Parameter, Table 2 ... 5 Changes to Serial Interface (SER/PAR SEL = 1) Section .. 25 Change to DC Accuracy Parameter, Table 3 ... 7 Changes to Daisy-Chain Mode (DCEN = 1, SER/PAR SEL = 1) . 27 Added %FSR to Terminology Section ... 19 Changes to Layout Section .. 30 Updated Outline Dimension .. 31 3/09—Rev. 0 to Rev. A Changes to Ordering Guide .. 31 Changes to Features .. 1 Changes to Table 1 .. 3 Changes to Table 2 .. 5 7/08—Revision 0: Initial Version Rev. D | Page 2 of 32 Document Outline Features Applications Functional Block Diagram General Description Product Highlights Table of Contents Revision History Specifications AD7656-1 AD7657-1 AD7658-1 Timing Specifications Absolute Maximum Ratings Thermal Resistance ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Terminology Theory of Operation Converter Details Track-and-Hold Amplifiers Analog Input ADC Transfer Function Internal/External Reference Typical Connection Diagram Driving the Analog Inputs Interface Options Parallel Interface (SER/PAR SEL = 0) Software Selection of ADCs Changing the Analog Input Range (H/S SEL = 0) Changing the Analog Input Range (H/S SEL = 1) Serial Interface (SER/PAR SEL = 1) Serial Read Operation Daisy-Chain Mode (DCEN = 1, SER/ SEL = 1) Standby/Partial Power-Down Modes of Operation (SER/PAR SEL = 0 or 1) Application Hints Layout Power Supply Configuration Outline Dimensions Ordering Guide