link to page 3 link to page 5 link to page 7 link to page 9 link to page 9 link to page 10 link to page 11 link to page 12 link to page 15 link to page 15 link to page 16 link to page 16 link to page 18 link to page 18 link to page 19 link to page 20 link to page 20 link to page 21 link to page 22 link to page 22 link to page 23 link to page 23 link to page 24 link to page 24 link to page 24 link to page 24 link to page 24 link to page 24 link to page 24 link to page 24 link to page 24 link to page 24 link to page 24 link to page 24 link to page 24 link to page 26 link to page 27 link to page 27 link to page 27 link to page 27 link to page 27 link to page 28 link to page 28 link to page 29 link to page 30 link to page 31 link to page 31 link to page 31 AD7997/AD7998TABLE OF CONTENTS AD7997 Specifications... 3 Serial Bus Address .. 23 AD7998 Specifications... 5 Writing to the AD7997/AD7998 .. 24 I2C Timing Specifications .. 7 Writing to the Address Pointer Register for a Subsequent Read.. 24 Absolute Maximum Ratings.. 9 Writing a Single Byte of Data to the Alert Status Register or ESD Caution.. 9 Cycle Register.. 24 Pin Configuration and Pin Function Descriptions.. 10 Writing Two Bytes of Data to a Limit, Hysteresis, or Terminology .. 11 Configuration Register .. 24 Typical Performance Characteristics ... 12 Reading Data from the AD7997/AD7998... 26 Circuit Information .. 15 ALERT/BUSY Pin .. 27 Converter Operation.. 15 SMBus ALERT .. 27 Typical Connection Diagram ... 16 BUSY .. 27 Analog Input ... 16 Placing the AD7997-1/AD7998-1 into High Speed Mode ... 27 Internal Register Structure .. 18 The Address Select (AS) Pin ... 27 Address Pointer Register ... 18 Modes of Operation ... 28 Configuration Register .. 19 Mode 1—Using the CONVST Pin ... 28 Conversion Result Register ... 20 Mode 2 – COMMAND MODE ... 29 Limit Registers .. 20 Mode 3—Automatic Cycle Interval Mode.. 30 Alert Status Register (CH1 to CH4) .. 21 Outline Dimensions ... 31 Cycle Timer Register.. 22 Ordering Guide .. 31 Sample Delay and Bit Trial Delay... 22 Related Parts in I2C-Compatible ADC Product Family.. 31 Serial Interface .. 23 REVISION HISTORY9/04—Revision 0: Initial Version Rev. 0 | Page 2 of 32 Document Outline FEATURES GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM PRODUCT HIGHLIGHTS AD7997 SPECIFICATIONS AD7998 SPECIFICATIONS I2C TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND PIN FUNCTION DESCRIPTIONS TERMINOLOGY TYPICAL PERFORMANCE CHARACTERISTICS CIRCUIT INFORMATION CONVERTER OPERATION TYPICAL CONNECTION DIAGRAM ANALOG INPUT INTERNAL REGISTER STRUCTURE ADDRESS POINTER REGISTER CONFIGURATION REGISTER CONVERSION RESULT REGISTER LIMIT REGISTERS DATAHIGH Register CH1/CH2/CH3/CH4 DATALOW Register CH1/CH2/CH3/CH4 Hysteresis Register (CH1/CH2/CH3/CH4) Using the Limit Registers to Store Min/Max Conversion Result ALERT STATUS REGISTER (CH1 TO CH4) CYCLE TIMER REGISTER SAMPLE DELAY AND BIT TRIAL DELAY SERIAL INTERFACE SERIAL BUS ADDRESS WRITING TO THE AD7997/AD7998 WRITING TO THE ADDRESS POINTER REGISTER FOR A SUBSEQUENT REA WRITING A SINGLE BYTE OF DATA TO THE ALERT STATUS REGISTER O WRITING TWO BYTES OF DATA TO A LIMIT, HYSTERESIS, OR CONFIGU READING DATA FROM THE AD7997/AD7998 ALERT/BUSY PIN SMBus ALERT BUSY PLACING THE AD7997-1/AD7998-1 INTOHIGH SPEED MODE THE ADDRESS SELECT (AS) PIN MODES OF OPERATION MODE 1—USING THE PIN MODE 2 – COMMAND MODE MODE 3—AUTOMATIC CYCLE INTERVAL MODE OUTLINE DIMENSIONS ORDERING GUIDE RELATED PARTS IN I2C-COMPATIBLE ADC PRODUCT FAMILY