Isolated Sigma-Delta Modulator Data Sheet AD7400 FEATURES GENERAL DESCRIPTION 1 10 MHz clock rate The AD7400 is a second-order, sigma-delta (-) modulator Second-order modulator that converts an analog input signal to a high speed, 1-bit data 16 bits no missing codes stream with on-chip digital isolation based on Analog Devices, 2 LSB INL typical at 16 bits Inc. iCoupler technology. The AD7400 operates from a 5 V 3.5 V/C maximum offset drift power supply and accepts a differential input signal of 200 mV On-board digital isolator (320 mV full scale). The analog input is continuously sampled On-board reference by the analog modulator, eliminating the need for external Low power operation: 18 mA maximum at 5.25 V sample-and-hold circuitry. The input information is contained 40C to +105C operating range in the output stream as a density of ones with a data rate of 16-lead SOIC package 10 MHz. The original information can be reconstructed with an Safety and regulatory approvals appropriate digital filter. The serial I/O can use a 5 V or a 3 V UL recognition supply (VDD2). 5000 V rms for 1 minute per UL 1577 The serial interface is digitally isolated. High speed CMOS, CSA Component Acceptance Notice 5A combined with monolithic air core transformer technology, VDE Certificate of Conformity means the on-chip isolation provides outstanding performance DIN V VDE V 0884-10 (VDE V 0884-10):2006-12 characteristics superior to alternatives such as optocoupler V = 891 V peak IORM devices. The part contains an on-chip reference. The AD7400 is APPLICATIONS offered in a 16-lead SOIC and has an operating temperature range of 40C to +105C. AC motor controls Data acquisition systems An external clock version, AD7401, is also available. A/D + opto-isolator replacements 1 Protected by U.S. Patents 5,952,849 6,873,065 and 7,075,329. FUNCTIONAL BLOCK DIAGRAM V V DD1 DD2 AD7400 V + IN - ADC V IN UPDATE WATCHDOG ENCODE DECODE MDAT REF CONTROL LOGIC UPDATE WATCHDOG ENCODE MCLKOUT DECODE GND GND 1 2 Figure 1. Rev. H Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20062018 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. T/H BUF 04718-001AD7400 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Typical Performance Characteristics ..............................................9 Applications ....................................................................................... 1 Terminology .................................................................................... 12 General Description ......................................................................... 1 Theory of Operation ...................................................................... 13 Functional Block Diagram .............................................................. 1 Circuit Information .................................................................... 13 Revision History ............................................................................... 2 Analog Input ............................................................................... 13 Specifications ..................................................................................... 3 Differential Inputs ...................................................................... 14 Timing Specifications .................................................................. 4 Digital Filter ................................................................................ 15 Insulation and Safety-Related Specifications ............................ 5 Applications Information .............................................................. 17 Regulatory Information ............................................................... 5 Grounding and Layout .............................................................. 17 DIN V VDE V 0884-10 (VDE V 0884-10) Insulation Evaluating the AD7400 Performance ...................................... 17 Characteristics .............................................................................. 6 Insulation Lifetime ..................................................................... 17 Absolute Maximum Ratings ............................................................ 7 Outline Dimensions ....................................................................... 18 ESD Caution .................................................................................. 7 Ordering Guide .......................................................................... 18 Pin Configuration and Function Descriptions ............................. 8 REVISION HISTORY 5/2018Rev. G to Rev. H 4/2011Rev. C to Rev. D Changes to Minimum External Air Gap (Clearance) Parameter, Changes to Dynamic Input Current Parameter, Table 1 .............. 3 Minimum External Tracking (Creepage) Parameter, Tracking Resistance (Comparative Tracking Index) Parameter, and 1/2011Rev. B to Rev. C Isolation Group Parameter, Table 3, and 5000 V rms Isolation Changes to Features Section ............................................................ 1 Voltage Parameter, Table 4 .............................................................. 5 Changes to Input-to-Output Momentary Withstand Voltage Added Note 1 and Note 2, Table 3 Renumbered Sequentially .. 5 Parameter, Table 3, UL Column, Table 4, and Note 1, Table 4 ........... 5 Changes to Ordering Guide .................................................................... 18 6/2013Rev. F to Rev. G Changes to Figure 12 and Figure 13 ............................................. 10 9/2007Rev. A to Rev. B Updated VDE Certification Throughout ...................................... 1 3/2012Rev. E to Rev. F Changes to Table 6 ............................................................................. 7 Changed IDD1 Parameter from 12 mA to 13 mA, Table 1 ............ 3 12/2006Rev. 0 to Rev. A 7/2011Rev. D to Rev. E Changes to Features .......................................................................... 1 Changes to Minimum External Air Gap (Clearance) Parameter, Changes to Table 6 ............................................................................. 7 Table 3 and Minimum External Tracking (Creepage) Parameter, Changes to Analog Input Section ................................................. 13 Table 3 ................................................................................................ 5 Changes to Figure 26 ...................................................................... 15 Changes to Figure 5 Pin 1 Description, Table 8 and Pin 7 Description, Table 8 .......................................................................... 8 1/2006Revision 0: Initial Version Rev. H Page 2 of 20