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 4 link to page 6 link to page 8 link to page 8 link to page 8 link to page 8 link to page 9 link to page 11 link to page 20 link to page 21 link to page 21 link to page 22 link to page 23 link to page 23 link to page 23 link to page 23 link to page 24 link to page 24 link to page 25 link to page 26 link to page 26 link to page 26 link to page 26 link to page 27 link to page 28 link to page 28 link to page 29 link to page 30 ADA4940-1/ADA4940-2Data SheetTABLE OF CONTENTS Features .. 1 Applications Information .. 23 Applications ... 1 Analyzing an Application Circuit .. 23 General Description ... 1 Setting the Closed-Loop Gain .. 23 Functional Block Diagrams ... 1 Estimating the Output Noise Voltage .. 23 Revision History ... 3 Impact of Mismatches in the Feedback Networks ... 24 Specifications ... 4 Calculating the Input Impedance of an Application Circuit ... 24 VS = 5 V .. 4 Input Common-Mode Voltage Range ... 25 VS = 3 V .. 6 Input and Output Capacitive AC Coupling .. 26 Absolute Maximum Ratings .. 8 Setting the Output Common-Mode Voltage .. 26 Thermal Resistance .. 8 DISABLE Pin .. 26 Maximum Power Dissipation ... 8 Driving a Capacitive Load ... 26 ESD Caution .. 8 Driving a High Precision ADC .. 27 Pin Configurations and Function Descriptions ... 9 Layout, Grounding, and Bypassing .. 28 Typical Performance Characteristics ... 11 ADA4940-1 LFCSP Example .. 28 Test Circuits ... 20 Outline Dimensions ... 29 Terminology .. 21 Ordering Guide .. 30 Definition of Terms .. 21 Theory of Operation .. 22 Rev. C | Page 2 of 32 Document Outline Features Applications General Description Functional Block Diagrams Revision History Specifications VS = 5 V +DIN or –DIN to VOUT, dm Performance VOCM to VOUT, cm Performance General Performance VS = 3 V +DIN or –DIN to VOUT, dm Performance VOCM to VOUT, cm Performance General Performance Absolute Maximum Ratings Thermal Resistance Maximum Power Dissipation ESD Caution Pin Configurations and Function Descriptions Typical Performance Characteristics Test Circuits Terminology Definition of Terms Differential Voltage Common-Mode Voltage (CMV) Common-Mode Offset Voltage Differential VOS, Differential CMRR, and VOCM CMRR Balance Theory of Operation Applications Information Analyzing an Application Circuit Setting the Closed-Loop Gain Estimating the Output Noise Voltage Impact of Mismatches in the Feedback Networks Calculating the Input Impedance of an Application Circuit Terminating a Single-Ended Input Input Common-Mode Voltage Range Input and Output Capacitive AC Coupling Setting the Output Common-Mode Voltage DISABLE Pin Driving a Capacitive Load Driving a High Precision ADC Layout, Grounding, and Bypassing ADA4940-1 LFCSP Example Outline Dimensions Ordering Guide