Impedance Meters and Analyzers

Impedance meters (ZMs) or RLC meters measure resistance and reactance of two-terminal devices. Measurement is made by driving the device under test (DUT) with a sine-wave voltage or current and measuring the resulting current or voltage. Then a microcontroller computes the resistance or reactance resulting in a displayed value of R, L, or C. A more complete device model that includes series or parallel R and reactance also measures phase between device voltage and current and uses the phase difference to determine the resistive and reactive components of the device impedance.

Impedance analyzers (ZAs) extend the ZM concept by making frequency a variable that is swept over a set range, with source output and response input. ZAs are effectively two-port measurement instruments of limited (relative to TPAs) port versatility that can produce not only impedance plots with frequency but can also measure amplifier or feedback-loop frequency response of magnitude and phase relative to the source. They are in the category of wideband network analyzers in that the response circuits are not tuned as in spectrum analyzers but are wideband, as are oscilloscope or data-acquisition-system amplifiers.

ZM200 Z Meters  

The ZM204 prototype analog electronics is working. The ZM202 is under prototype test. The ZM201 is in design.

ZM200 Series

ZM201

ZM202

ZM203

ZM204

ZM205

ZM206

Priority, Phase

3, C2

2, C3

4, C1

1, D2

6, C1

5, C1

V range, dec

1

2

2

2

2

2

V range, fs

200 mV, 2 V

25 mV,

2.5 V

2.5 mV, 2.5 V

40 mV, 4 V

80 mV, 8 V

40 mV, 4 V

I range, dec

6

6

6

6

6

5

I range, fs

20 nA, 20 mA

25 nA, 25 mA

250 nA, 250 mA

200 nA, 200 mA

4 μA, 4 A

20 μA, 2 A

Z, R range, dec

7

8

8

8

8

7

Z, R range, fs

10 Ω, 100 MΩ

1 Ω, 100 MΩ

100 mΩ, 10 MΩ

0.2 Ω, 20 MΩ

20 mΩ, 2 MΩ

20 mΩ, 200 kΩ

Frequency range, dec

1

1

3

1

5

2

ZM Freq range

16 Hz,

160 Hz

80 Hz, 800 Hz

80 Hz,

80 kHz

80 Hz, 800 Hz

1 Hz, 100 kHz

80 Hz, 8 kHz

L, C range, dec

8

9

11

9

13

9

L range, fs

10 mH, 1 MH

200 μH, 200 kH

200 nH, 20 kH

40 μH, 40 kH

100 nH, 1 MH

400 nH, 400 H

C range, fs

10 pF, 1 mF

2 pF, 2 mF

200 fF, 20 mF

10 pF, 10 mF

2.5 pF, 25 F

100 nF, 0.1 F

Generator type

μC DAC, LPF

Wien-brg osc

20 MHz trap. WG

quadrature osc

VFC

sin, cos DACs

Gen. ampl. control

μC

hw pk det, LPF, JFET

μC

hw pk det, LPF, JFET

window comparator

sin, cos DACs

Bridge type

Fb SMU-H

Fb SMU-H

Switched I-src div

Fb SMU-H

Fb SMU-L

SMU-H

Phase detector

zc cmprs cntr

PLL I-Q gen, aSw mpyr

 dual analog mpyr,

sync avgr

aSw mpyr,

LPF

none

analog mpyr, LPF

DVM

2000 cnt

μC Σ-Δ

dual 12-bit ADC

14-bit VFC,

μC Σ-Δ

12-bit SA ADC

μC 16-bit cntr

14-bit ADC

Power Supply

5 V, 0.2 A

2 W

5 V, 200 mA

2 W

5 V, 400 mA

12 V, 100 mA

4.4 W

5 V, 200 mA

12 V, 250 mA

50 W

12 V, 4.5 A in

12 V, 4 A

5 V, 50 mA

50 W

5 V, 2.6 A

25 W

Front-Panel

3.3-digit LED, 4-sw, digiknob, mode LEDs

3.3-digit LED, 4-sw, digiknob, mode LEDs

4-digit LED,

4-sw,

unit & mode LEDs

16-char LCD, 4-sw, mode LEDs

4-digit LED, 4-sw, mode LEDs

16 char LCD, 4-sw, mode LEDs

Proto μC, μC

μDAS, ATmega8515

MC2, ATmega8515

miniDAS, ATmega328

Huron, ATmega8515

ATmega328

MC2, PG2A

ATmega328

Notes

Min cost & analog parts, max μC

BK875A-derived

Wide L, C range;

max digital; sin-cos gen

General-purpose ZM,

datalogging

Power RCL,

VFC-based

Min analog,

PG2A pwr SMU-H

 ZA200 Z Analyzers  

The Innovatia ZAs are wideband, not narrowband, instruments. Wideband ZAs do not have as large of a dynamic range, but they are simpler (fewer parts) and lower in cost.  

The ZA201 prototype has been functioning but the design is being modified. The ZA202 is in concept phase.

ZA200 Series

ZA201

ZA202

V range, dec

1

2

V range, fs

250 mV, 2.5 V

25 mV, 2.5 V

I range, dec

3

3

I range, fs

100 μA, 1 A

10 μA, 10 mA

ZA Freq range, dec

3

7

ZA Freq range

80 Hz, 80 kHz

80 Hz, 8 MHz

Z, R range, dec

8

5

Z, R range, fs

250 mΩ, 25 kΩ

2.5 Ω, 250 kΩ

L, C range, dec

8

12

L range, fs

500 nH, 50 H

500 nH, 500 H

C range, fs

100 pF, 10 mF

1 pF, 1 mF

Bridge type

Innovatia

Innovatia

Generator type

XR2206

AD9833

Phase acq

cmprs, XOR gate, LPF  μC ADC

aSW mpyr, LPF μC ADC

Magnitude acq

wideband PGA, sync S&H, μC ADC

bandpass PGA, |v|, LPF μC ADC

FRA Freq range

5 Hz, 500 kHz

1 Hz, 10 MHz

Magnitude inaccuracy

1 %

1 %

Phase resolution, deg

0.5

0.5

Board Configuration

μC&FP, ZA, PS

μC&FP, ZA, PS

Front-Panel

8-char LED, 4-sw

Graphic LCD, 4-sw, digiknob

μC

μM  MC56F8025 (M0B)

MC56F8025 (M0B)

Power Supply

12 V, 1 A in

5 V, 1.1 A

12 V, 50 mA

12 W

12 V, 0.25 A in

5 V, 100 mA

12 V, 50 mA

2.5 W

Development Phase & Notes

Design (D0)

power-circuit applications

 Concept (C1)

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