AD5934

Rev. 0 | Page 2 of 32

TABLE OF CONTENTS

Features .............................................................................................. 1

Applications....................................................................................... 1

General Description ......................................................................... 1

Functional Block Diagram .............................................................. 1

Specifications..................................................................................... 3

I2C Serial Interface Timing Characteristics .................................. 5

Absolute Maximum Ratings............................................................ 6

ESD Caution.................................................................................. 6

Pin Configuration and Descriptions.............................................. 7

Typical Performance Characteristics ............................................. 8

Terminology .................................................................................... 10

System Description......................................................................... 11

Transmit Stage............................................................................. 12

Frequency Sweep Command Sequence................................... 13

Receive Stage ............................................................................... 13

DFT Operation ........................................................................... 13

Impedance Calculation .................................................................. 14

Magnitude Calculation .............................................................. 14

Gain Factor Calculation ............................................................ 14

Impedance Calculation Using Gain Factor............................. 14

Gain Factor Variation with Frequency .................................... 14

Two-Point Calibration ............................................................... 15

Two-Point Gain Factor Calculation ......................................... 15

Gain Factor Setup Configuration............................................. 15

Gain Factor Recalculation ......................................................... 15

Gain Factor Temperature Variation......................................... 16

Impedance Error ........................................................................ 16

Performing a Frequency Sweep .................................................... 18

Register Map ................................................................................... 19

Control Register ......................................................................... 19

Start Frequency Register ........................................................... 20

Frequency Increment Register.................................................. 20

Number of Increments Register ............................................... 21

Number of Settling Time Cycles Register ............................... 21

Status Register............................................................................. 22

Real and Imaginary Data Registers (16 Bits).......................... 22

Serial Bus Interface......................................................................... 23

General I2C Timing.................................................................... 23

Writing/Reading to the AD5934 .............................................. 24

Block Write.................................................................................. 24

AD5934 Read Operations ......................................................... 25

Typical Applications....................................................................... 26

Biomedical: Noninvasive Blood impedance Measurement .. 26

Sensor/Complex Impedance Measurement............................ 26

Electro-Impedance Spectroscopy............................................. 27

Choosing a Reference for the AD5934 ........................................ 28

Layout and Configuration............................................................. 29

Power Supply Bypassing and Grounding................................ 29

Outline Dimensions ....................................................................... 30

Ordering Guide .......................................................................... 30

REVISION HISTORY

6/05—Revision 0: Initial Version