link to page 16 AD7944Data SheetABSOLUTE MAXIMUM RATINGS Table 5. Stresses at or above those listed under Absolute Maximum ParameterRating Ratings may cause permanent damage to the product. This is a Analog Inputs stress rating only; functional operation of the product at these or any other conditions above those indicated in the operational IN+, IN− to GND1 −0.3 V to VREF + 0.3 V or ±130 mA section of this specification is not implied. Operation beyond Supply Voltage the maximum operating conditions for extended periods may REF, BVDD to GND, REFGND −0.3 V to +6.0 V affect product reliability. AVDD, DVDD, VIO to GND −0.3 V to +2.7 V ESD CAUTION AVDD, DVDD to VIO −6 V to +3 V Digital Inputs to GND −0.3 V to VIO + 0.3 V Digital Outputs to GND −0.3 V to VIO + 0.3 V Storage Temperature Range −65°C to +150°C Junction Temperature 150°C θ JA Thermal Impedance 20-Lead LFCSP (QFN) 30.4°C/W Lead Temperatures Vapor Phase (60 sec) 215°C Infrared (15 sec) 220°C 1 See the Analog Inputs section for an explanation of IN+ and IN−. Rev. C | Page 6 of 28 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION APPLICATION DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY THEORY OF OPERATION CIRCUIT INFORMATION CONVERTER OPERATION CONVERSION MODES OF OPERATION Transfer Functions TYPICAL APPLICATION DIAGRAM ANALOG INPUTS DRIVER AMPLIFIER CHOICE VOLTAGE REFERENCE INPUT Internal Reference, REF = 4.096 V (PDREF Low) External 1.2 V Reference and Internal Buffer (PDREF High) External Reference (PDREF High, REFIN Low) Reference Decoupling POWER SUPPLY DIGITAL INTERFACE DATA READING OPTIONS Reading During Conversion, Fast Host (Turbo or Normal Mode) Split Reading, Any Speed Host (Turbo or Normal Mode) Reading During Acquisition, Any Speed Host (Turbo or Normal Mode) CS\ MODE, 3-WIRE WITHOUT BUSY INDICATOR CS\ MODE, 3-WIRE WITH BUSY INDICATOR CS\ MODE, 4-WIRE WITHOUT BUSY INDICATOR CS\ MODE, 4-WIRE WITH BUSY INDICATOR CHAIN MODE WITHOUT BUSY INDICATOR CHAIN MODE WITH BUSY INDICATOR APPLICATIONS INFORMATION LAYOUT EVALUATING AD7944 PERFORMANCE OUTLINE DIMENSIONS ORDERING GUIDE