Datasheet

ManualsBrandsDigilent ManualsHardware410-246

1300 Henley Court

Pullman, WA 99163

509.334.6306

www.digilentinc.com

PmodIA™ Reference Manual

Revised January 20, 2016

This manual applies to the PmodIA rev. A

DOC#: 502-246

Other product and company names mentioned may be trademarks of their respective owners.

Page 1 of 5

Overview

The PmodIA is an impedance analyzer built around the Analog Devices AD5933 12-bit Impedance Converter

Network Analyzer.

1 Functional Description

The PmodIA utilizes Analog Devices AD5933 with its on-board frequency generator and analog-to-digital converter

(ADC) to be able to excite an external unknown impedance at a known frequency. This known frequency is sent

out through one of the SMA connectors. The frequency response is captured by the other SMA connector and sent

to the ADC and a discrete Fourier transform (DFT) is performed on sampled data, storing the real and imaginary

parts of the solution in the on-chip data registers. The magnitude of the unknown impedance as well as the

relative phase of the impedance at each point in the generated frequency sweep can be calculated from these two

data words.

The PmodIA.

 Impedance analyzer with 12-bit impedance

converter

 Measure impedance values ranging from 100Ω

to 10 MΩ.

 Programmable frequency sweep

 Programmable gain amplifier

 Optional external clock generation

 Small PCB size for flexible designs 1.6 in × 0.8

in (4.1 cm × 2.0 cm)

 2×4-pin connector with I²C interface

 Follows Digilent Interface Specification

 Library and example code available in resource

center

Features include:

Summary of content (5 pages)

PAGE 1
300 Henley Court Pullman, WA 99163 509.334.6306 www.digilentinc.com PmodIA™ Reference Manual Revised January 20, 2016 This manual applies to the PmodIA rev. A Overview The PmodIA is an impedance analyzer built around the Analog Devices AD5933 12-bit Impedance Converter Network Analyzer. Features include:          Impedance analyzer with 12-bit impedance converter Measure impedance values ranging from 100Ω to 10 MΩ.
PAGE 2
PmodIA™ Reference Manual 1.1 I2C Interface The PmodIA acts as a slave device using I2C communication protocol. The I2C interface standard uses two signal lines. These are I2C data and I2C clock. These signals map to the serial data (SDA) and serial clock (SCL) respectively on the PmodIA. (See Table 1.) The following instructions explain how to read and write to the device. You must consider two protocols when writing to the PmodIA: the write byte/command byte and the block write.
PAGE 3
PmodIA™ Reference Manual 1.3 Setting up a Frequency Sweep The electrical impedance, 𝑍, of a circuit can vary over a range of frequencies. The PmodIA allows you to easily set up a frequency sweep to find the impedance characteristics of a circuit. First, you must set up an I2C interface between the host board and the PmodIA. The PmodIA requires three pieces of information to perform a frequency sweep: a starting frequency, the number of steps in the sweep, and the frequency increment after each step.
PAGE 4
PmodIA™ Reference Manual 2) Enter the initialize mode by sending an initialize with start frequency command to the control register. This allows the circuit being measured to reach its steady state. 3) Start the frequency sweep by sending the start frequency sweep command to the control register. 1.4 Impedance Calculations The analog-to-digital converter samples the frequency response from unknown impedances at up to 1MSPS with 12-bit resolution for every point in the frequency sweep.