AD5934YRSZ Analog Devices

250 kSPS, 12-Bit Impedance Converter, Network Analyzer Data Sheet AD5934 FEATURES GENERAL DESCRIPTION Programmable output peak-to-peak excitation voltage to a The AD5934 is a high precision impedance converter system maximum frequency of 100 kHz solution that combines an on-board frequency generator with a 2 Programmable frequency sweep capability with serial I C 12-bit, 250 kSPS, analog-to-digital converter (ADC). The interface frequency generator allows an external complex impedance to Frequency resolution of 27 bits (<0.1 Hz) be excited with a known frequency. The response signal from Impedance measurement range from 1 k to 10 M the impedance is sampled by the on-board ADC and a discrete Capable of measuring 100 to 1 k with additional circuitry Fourier transform (DFT) is processed by an on-board DSP Phase measurement capability engine. The DFT algorithm returns a real (R) and imaginary (I) System accuracy of 0.5% data-word at each output frequency. 2.7 V to 5.5 V power supply operation Once calibrated, the magnitude of the impedance and relative Temperature range: 40C to +125C phase of the impedance at each frequency point along the sweep 16-lead SSOP package is easily calculated using the following two equations: APPLICATIONS 2 2 Magnitude = R + I Electrochemical analysis 1 Bioelectrical impedance analysis Phase = tan (I/R) Impedance spectroscopy A similar device, available from Analog Devices, Inc., is the Complex impedance measurement AD5933, which is a 2.7 V to 5.5 V, 1 MSPS, 12-bit impedance Corrosion monitoring and protection equipment converter, with an internal temperature sensor, available in a Biomedical and automotive sensors 16-lead SSOP. Proximity sensing Nondestructive testing Material property analysis Fuel/battery cell condition monitoring FUNCTIONAL BLOCK DIAGRAM MCLK AVDD DVDD DDS CORE DAC (27 BITS) R VOUT OUT V SCL BIAS 2 I C INTERFACE SDA Z() AD5934 REAL IMAGINARY REGISTER REGISTER RFB 1024-POINT DFT VIN ADC GAIN (12 BITS) LPF VDD/2 AGND DGND Figure 1. Rev. E 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 20052017 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com 05325-001AD5934 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Performing a Frequency Sweep .................................................... 19 Applications ....................................................................................... 1 Register Map ................................................................................... 20 General Description ......................................................................... 1 Control Register (Register Address 0x80, Register Address 0x81) ............................................................................................. 20 Functional Block Diagram .............................................................. 1 Start Frequency Register (Register Address 0x82, Register Revision History ............................................................................... 3 Address 0x83, Register Address 0x84) .................................... 21 Specifications ..................................................................................... 4 Frequency Increment Register (Register Address 0x85, 2 I C Serial Interface Timing Characteristics .............................. 6 Register Address 0x86, Register Address 0x87) ..................... 21 Absolute Maximum Ratings ............................................................ 7 Number of Increments Register (Register Address 0x88, ESD Caution .................................................................................. 7 Register Address 0x89) .............................................................. 22 Pin Configuration and Function Descriptions ............................. 8 Number of Settling Time Cycles Register (Register Address 0x8A, Register Address 0x8B) .................................................. 22 Typical Performance Characteristics ............................................. 9 Status Register (Register Address 0x8F) .................................. 22 Terminology .................................................................................... 11 Real and Imaginary Data Registers (16 BitsRegister Address System Description ......................................................................... 12 0x94, Register Address 0x95, Register Address 0x96, Register Transmit Stage ............................................................................. 13 Address 0x97) .............................................................................. 23 Frequency Sweep Command Sequence ................................... 14 Serial Bus Interface ......................................................................... 24 Receive Stage ............................................................................... 14 2 General I C Timing .................................................................... 24 DFT Operation ........................................................................... 14 Writing/Reading to the AD5934 .............................................. 25 Impedance Calculation .................................................................. 15 Block Write .................................................................................. 25 Magnitude Calculation .............................................................. 15 Read Operations ......................................................................... 26 Gain Factor Calculation ............................................................ 15 Typical Applications ....................................................................... 27 Impedance Calculation Using Gain Factor ............................. 15 Measuring Small Impedances ................................................... 27 Gain Factor Variation with Frequency .................................... 15 Biomedical: Noninvasive Blood impedance Measurement .. 28 2-Point Calibration ..................................................................... 16 Sensor/Complex Impedance Measurement ............................ 29 2-Point Gain Factor Calculation .............................................. 16 Electro-Impedance Spectroscopy ............................................. 29 Gain Factor Setup Configuration ............................................. 16 Layout and Configuration ............................................................. 30 Gain Factor Recalculation ......................................................... 16 Power Supply Bypassing and Grounding ................................ 30 Gain Factor Temperature Variation ......................................... 17 Outline Dimensions ....................................................................... 31 Impedance Error ......................................................................... 17 Ordering Guide .......................................................................... 31 Measuring the Phase Across an Impedance ........................... 17 Rev. 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