link to page 7 link to page 7 Data SheetAD7688TIMING SPECIFICATIONS −40°C to +85°C, VDD = 4.5 V to 5.5 V, VIO = 2.3 V to 5.5 V or VDD + 0.3 V, whichever is the lowest, unless otherwise stated. See Figure 3 and Figure 4 for load conditions. Table 4. ParameterSymbolMinTypMaxUnit Conversion Time: CNV Rising Edge to Data Available tCONV 0.5 1.6 µs Acquisition Time tACQ 400 ns Time Between Conversions tCYC 2 µs CNV Pulse Width (CS Mode) tCNVH 10 ns SCK Period (CS Mode) tSCK 15 ns SCK Period (Chain Mode) tSCK VIO Above 4.5 V 17 ns VIO Above 3 V 18 ns VIO Above 2.7 V 19 ns VIO Above 2.3 V 20 ns SCK Low Time tSCKL 7 ns SCK High Time tSCKH 7 ns SCK Falling Edge to Data Remains Valid tHSDO 5 ns SCK Falling Edge to Data Valid Delay tDSDO VIO Above 4.5 V 14 ns VIO Above 3 V 15 ns VIO Above 2.7 V 16 ns VIO Above 2.3 V 17 ns CNV or SDI Low to SDO D15 MSB Valid (CS Mode) tEN VIO Above 4.5 V 15 ns VIO Above 2.7 V 18 ns VIO Above 2.3 V 22 ns CNV or SDI High or Last SCK Falling Edge to SDO High Impedance (CS Mode) tDIS 25 ns SDI Valid Setup Time from CNV Rising Edge (CS Mode) tSSDICNV 15 ns SDI Valid Hold Time from CNV Rising Edge (CS Mode) tHSDICNV 0 ns SCK Valid Setup Time from CNV Rising Edge (Chain Mode) tSSCKCNV 5 ns SCK Valid Hold Time from CNV Rising Edge (Chain Mode) tHSCKCNV 5 ns SDI Valid Setup Time from SCK Falling Edge (Chain Mode) tSSDISCK 3 ns SDI Valid Hold Time from SCK Falling Edge (Chain Mode) tHSDISCK 4 ns SDI High to SDO High (Chain Mode with BUSY indicator) tDSDOSDI VIO Above 4.5 V 15 ns VIO Above 2.3 V 26 ns Rev. B | Page 5 of 28 Document Outline Features Applications Application Diagram General Description Table of Contents Revision History Specifications Timing Specifications Absolute Maximum Ratings Thermal Resistance ESD Caution Pin Configuration and Function Descriptions Terminology Typical Performance Characteristics Circuit Information Converter Operation Transfer Functions Typical Connection Diagram Analog Input Driver Amplifier Choice Single-to-Differential Driver Voltage Reference Input Power Supply Supplying the ADC from the Reference Digital Interface /CS Mode 3-Wire, No BUSY Indicator /CS Mode 3-Wire with BUSY Indicator /CS Mode 4-Write, No BUSY Indicator /CS Mode 4-Wire with BUSY Indicator Chain Mode, No BUSY Indicator Chain Mode with BUSY Indicator Application Hints Layout Evaluating the AD7688 Performance Outline Dimensions Ordering Guide