Analog Discovery Impedance Analyzer Reference
Manual
The Impedance Analyzer Instrument in WaveForms is made easier to use by the reference resistors and
relays that come pre-loaded on the Impedance Analyzer board. The Analog Discovery can automatically
select the most appropriate component for the job that it needs to do. The Impedance Analyzer is equipped
with the 2×15 Analog Discovery connector, which makes it compatible with Analog Discovery Legacy,
Analog Discovery 2, and Analog Discovery 2-NI Edition.
Note: Use of the Impedance Analyzer requires WaveForms version 3.8.2 or later.
Overview
Features
• Equipped with automatically selectable reference resistances
• Compatible with the Analog Discovery Legacy, Analog Discovery 2, and Analog Discovery NI-
Edition
• Allows auto-scaling
Compatible Products
The Analog Discovery Impedance Analyzer is compatible with the following:
• Analog Discovery Legacy
• Analog Discovery 2
• Analog Discovery 2-NI Edition
About this Document
This reference manual applies to Revision A of the Analog Discovery Impedance Analyzer.
Functional Description
Connectors and Jumpers
J1 - 2×15 Analog Discovery connector - Interfaces the Impedance Analyzer with the Analog Discovery
J2 - 1×2 Terminal Bloc - Used for connecting in circuit the unknown impedance
Digital Pins used for configuration
The Analog Discovery's digital I/O pins are used to control the relays in order to select the needed value for
the reference impedance. Each relay driver uses two I/Os to control one relay.
Measuring the impedance
The Analog Discovery Impedance Analyzer is used to analyze capacitive and inductive elements. It uses the
WaveGen 1, Oscilloscope device instruments, and a reference resistor.
The impedance analyzer circuit is constructed as in the circuit below. Load represents the inductive or
capacitive item to be analyzed and Resistor is the reference resistor that is already loaded on the board. The
resistor value depends on the load value and frequency.
The approximate resistor needed for different loads are the following:
Capacitance
Ref Resistor
Inductance
100 pF
1 MΩ
1 nF
100 kΩ
10 nF
10 kΩ
100 nF
1 kΩ
1 uH
1 uF
1 kΩ
10 uH
10 uF
100 Ω
100 uH
100 uF
10 Ω
1 mH
Power
The device is powered through the 5V user power supply from the Analog Discovery. It requires
approximately 25mA
Software Support
The Analog Discovery Impedance Analyzer is controlled with the Analog Discovery through the use of
WaveForms' Impedance Analyzer instrument. When the instrument is started, the Scope and WaveGen are
stopped and their status shows “Busy”. The Impedance Analyzer takes control over these instruments while
running.
When using the Analog Discovery Impedance Analyzer module, select “Adapter” in the interface, after the
resistor field. The application will use the power supplies and digital I/Os to control the module to switch
between the resistor values: 10R, 100R, 1k, 10k, 100k, 1M.
Additional Information
• WaveForms can be downloaded from the WaveForms Resource Center.
• Documentation and installation instructions can be found in the WaveForms Reference Manual.
• The Analog Discovery Impedance Analyzer Schematic can be found here.
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