LCR Application Guide

LCR Application Guide
LCR
Application Guide
1. MLCC (Multi-Layer Ceramic Capacitors )
p. 1-3
2. Electrolytic capacitors
p. 4-6
3. Tantalum capacitors
p. 7-8
4. Conductive polymer capacitors
p. 9-11
5. Inductors (Coils)
p. 12-15
6. Electric Transformers
p. 16-19
7. RFID (Contactless IC cards, Contactless IC tags)
p.20-22
8. Piezoelectric elements
p.23-25
MLCC (Multi-Layer Ceramic Capacitors )
There are two types of MLCC: a high-dielectric-constant type whose capacitance varies with the measurement
voltage and a temperature-compensated type whose capacitance does not vary. The measurement conditions
used when defining capacitance are set forth by separate JIS standards for temperature-compensated and
high-dielectric-constant MLCCs.
Setting example of measurement conditions
Parameters
Frequency
DC bias
Signal level
Measurement range
Speed
LowZ mode
Large capacitance:Cs-D, small capacitance:Cp-D
See the table below
OFF
Rated voltage or less
AUTO
SLOW2
OFF
*Otherwise, default settings are used.
*The above settings apply to an example measurement. Since optimal conditions vary with the measurement target,
specific settings should be determined by the instrument operator.
IEC 60384-21 Fixed surface mount multilayer capacitors of ceramic dielectric(JIS C5101-21)
Class 1: Temperature compensating type (EIA type C0G, JIS type CH etc.)(IEC30384-21)
Rated capacitance
Parameters
Rated voltage Measurement frequency
Voltage*1
C≦1000pF
C,D(tanδ)
All
C>1000pF
1MHz or 100kHz
(Reference 1MHz)
5Vrms or less
1kHz or 100kHz
(Reference 1kHz)
DC bias *2
_
IEC 60384-22 Fixed surface mount multilayer capacitors of ceramic dielectric(JIS C5101-22)
Class 2: High dielectric constant type (EIA type X5R, X7R, JIS type B, F etc.)(IEC30384-22)
Rated capacitance
Parameters
Rated voltage Measurement frequency
Voltage*1
DC bias *2
C,D(tanδ)
C≦100pF
100pF<C
≦10µF
C>10µF
All
6.3V or more
6.3V or less
All
1MHz
1kHz
1kHz
100Hz or 120Hz
1.0±0.2Vrms
1.0±0.2Vrms
0.5±0.2Vrms
0.5±0.2Vrms
_
*1 The measurement voltage (i.e., the voltage applied to the sample) is the voltage obtained by dividing the open-terminal
voltage by the output resistance and the sample.
*1 The measurement voltage (i.e., the voltage applied to the sample) can be calculated based on the open-terminal
voltage, the output resistance, and the sample’s impedance.
*2 CV mode is convenient when measuring a sample whose impedance is unknown and when measuring multiple
samples that exhibit a large degree of variability.
High-dielectric-constant capacitors
While high-dielectric-constant capacitors can
deliver high capacitance in a small package, their
capacitance tends to vary greatly with the
measurement voltage and temperature.
Capacitance
Capacitors bearing temperature characteristics
such as B, X5R, and X7R use high-dielectricconstant materials.
measured voltage
1
Products used
Mass Production Applications
Model
Measurement frequency
Features
3504-40
Ideal for large capacitance inspection
3504-50
120Hz,1kHz
High speed CV measurement
3504-60
3506-10
1kHz,1MHz
Ideal for small capacitance inspection, high repeatability
Research and Development Applications
Model
Measurement frequency
Features
IM3570
DC,4Hz to 5MHz
Frequency sweep with analyzer mode
*For more information, plese see the product catalog.
Selecting Parameter, Cs or Cp
Impedance according to frequency (when D is sufficiently small)
100Hz 120Hz
1pF
10pF
100pF
1nF
10nF
100nF
1uF
10uF
100uF
16Ω
13Ω
Choose CP
Depends on the case
Choose Cs
1kHz
160kΩ
16kΩ
1.6kΩ
160Ω
16Ω
1.6Ω
100kHz
1.6MegΩ
160kΩ
16kΩ
1.6kΩ
160Ω
16Ω
1.6Ω
160mΩ
16mΩ
1MHz
160kΩ
16kΩ
1.6kΩ
160Ω
16Ω
1.6Ω
160mΩ
16mΩ
1.6mΩ
Rp
C
Rs
Equivalent cuircuit of capacitors
Large capacitance capacitors: Rp can be
ignored since impedance of C is low.
Select series equivalent circuit modes.
Small capacitance capacitors: Rs can be
ignored since impedance of C is high.
Select series equivalent circuit modes.
Generally speaking, series equivalent circuit mode is used when measuring low-impedance elements
(approximately 100Ω or less) such as high-capacity capacitors, and parallel equivalent circuit mode is used
when measuring high-impedance elements (approximately 10 kΩ or greater) such as low-capacity capacitors.
An actual capacitor will behave as though Rs and Rp have been connected in series and in parallel,
respectively, with the ideal capacitor C, as in the figure. Rp is usually extremely large (megaohm-order or
greater), and Rs is extremely small (several ohms or less). An ideal capacitor’s reactance can be calculated
using the following equation based on its capacitance and frequency: Xc=1/j 2πf C[Ω]. When Xc is small, the
impedance when Rp is placed in parallel can be considered to be approximately equal to Xc. On the other
hand, because Rs cannot be ignored when Xc is small, the overall setup can be treated as a series equivalent
circuit with Xc and Rs. By contrast, when Xc is large, Rp cannot be ignored but Rs can, so the setup can be
treated as a parallel equivalent circuit.
2
Open-Circuit Voltage Mode (V) and Constant Voltage Mode (CV)
The no-load voltage is the voltage at the Hc terminal when no sample is connected. The voltage applied to the
sample is the result of dividing the no-load voltage by the output resistance and the sample.
In constant-voltage (CV) mode, the operator sets the voltage across the sample. The IM35xx reads the voltage
monitor value and generates a CV by applying feedback in software. Since the 3504-xx generates a CV in
hardware (using an analog circuit), that instrument is capable of constant-voltage measurement at high
speeds. Although the 3506-10 offers only no-load voltage (V) mode, it has lower impedance than other models
for samples for which the open-terminal voltage is approximately equal to the measurement voltage due to its
low output resistance (1Ω for 2.2 mF and greater ranges at 1 kHz and 20Ω for other conditions).
Open circuit voltage(V)
Output
Impeadance
Constant voltage(CV)
*1
Hc
Hp
DUT
Lc
Current detecting
circuit
Lp
voltage detecting circuit
Current flowing to DUT
*1 The output impedance varies depending on the model and on whether low-impedance high-precision
mode has been enabled. Please refer to the product specifications in the instruction manual.
3
Electrolytic capacitors
The measurement conditions used to define an electrolytic capacitor’s capacitance are set forth in IEC
standards, and the nominal values cited by capacitor manufacturers are measured values obtained in
accordance with those standards. However, because the capacitance values of electrolytic capacitors vary
greatly with the measurement frequency, capacitance values should be checked at the frequency at which the
circuit in question will actually be used.
Measure the equivalent series resistance (ESR), which includes factors such as the resistance of the
electrolytic capacitor’s internal electrodes and the electrolyte resistance, and the tangent D (tanδ) of the loss
angle under the same conditions as the capacitance.
Setting example of measurement conditions
Parameters
Frequency
DC bias
Signal level
Measurement range
Speed
LowZ mode
Cs-D-Rs
120Hz, frequency at which circuit will actually be used
ON 1.0V
0.5Vrms
AUTO
SLOW2
ON
*Otherwise, default settings are used.
*The above settings apply to an example measurement. Since optimal conditions vary with the measurement target,
specific settings should be determined by the instrument operator.
Fixed capacitors for use in electronic equipment Part 4: Sectional specification (IEC 60384-1)
Aluminium electrolytic capacitors with solid (MnO2) and non-solid electrolyte(JIS C5101-4)
Rated capacitance
Parameters
Rated voltage Measurement frequency Measurement voltage*1
C,D(tanδ)
Rs(ESR)
All
All
100Hz or 120Hz
0.5Vrms
DC bias *2
0.7 to 1.0V
*1 The measurement voltage (i.e., the voltage applied to the sample) is the voltage obtained by dividing the open-terminal
voltage by the output resistance and the sample.
*1 The measurement voltage (i.e., the voltage applied to the sample) can be calculated based on the open-terminal
voltage, the output resistance, and the sample’s impedance.
*2 DC bias need not be applied.
Low impedance high accuracy mode
0.1005 LowZ High Precision Model:OFF LowZ High Precision Model:ON 0.1004 Z[Ω]
In low impedance high accuracy mode,
the instrument’s output resistance is
reduced, and the measurement current is
applied repeatedly for increased
measurement precision. When measuring
a capacitor with a high capacitance of
greater than 100µF (and therefore low
impedance), low-impedance highprecision mode yields more stable
measurement. The graph below compares
repeatability when using the IM3570 to
make measurements with low-impedance
high-precision mode enabled and disabled
(100kHz, 1Ω range, 1V).
0.1003 0.1002 *The conditions under which lowimpedance high-precision mode can be
enabled vary with the instrument model.
Please refer to the instruction manual of
the instrument you are using.
0
20
40
60
Number of .mes
80
100
Repeated measurement of a resistance of approximately 100 mΩ
with the IM3570
4
Products used
Mass Production Applications
Model
Measurement frequency
Features
IM3523
DC, 40Hz to 200kHz Measurement time: 2ms, high cost performance
IM3533
DC, 1mHz to 200kHz Internal DC bias function, touch panel
Research and Development Applications
Model
Measurement frequency
Features
Frequency sweep with analyzer mode
IM3570
DC, 4Hz to 5MHz
IM9000
Optional equivalent cuircuit analysis firmware for the IM3570
IM3590
DC, 1mHz to 200kHz
Can measure ESR and ESL separately with its equivalent
circuit analysis function.
*For more information, plese see the product catalog.
Equivalent series resistance (ESR) and loss coefficient D (tanδ)
The figure below illustrates a standard equivalent circuit for an electrolytic capacitor.
At low frequencies (50 Hz to 1 kHz), the reactance (XL) resulting from the equivalent series inductance L is
extremely small and can be considered to be zero. The resistance and reactance components of each element
at this time are characterized by the vector relationship shown in the figure on a complex plane.
An ideal capacitor would have R = 0 and a loss coefficient D = 0, but since actual capacitors have various
resistance components, including electrode foil resistance, electrolyte resistance, and contact resistance of
leads and other parts, the equivalent series resistance ESR and loss coefficient D (tanδ) serve as useful
indicators for use in evaluating electrolytic capacitor quality.
Since the IM3533 and IM3536 can simultaneously measure and display four parameters, they can be used to
simultaneously check the reactance X, capacitance C, equivalent series resistance Rs, and loss coefficient D
as indicators for use in evaluating electrolytic capacitors, as shown in the example screenshots below.
r
R
(ESR)
C
C:Capacitance
r:Equivalent series resistance of
anodic oxidation coatings
R:Equivalent series resistance(ESR)
L:Equivalent series inductance
L
*General Description of Aluminum Electrolytic Capacitors
(NICHICON CORPORATION)
Equivalent circuit of Electrolytic capacitors
虚数
R
実数
Xc = Z sinθ=
θ
1
ωC
R = ESR = Z cosθ
δ
D = tanδ=
Xc
cosθ R
=
= ωCR
sinθ Xc
Z
Vector diagram Display example of IM3536
5
DC bias measurement function
Voltage
Electrolytic capacitors generally are available in
polarized and bipolar variants. A DC bias voltage
must be applied to polarized capacitors as
necessary to prevent application of a reverse
voltage.
DC bias voltage
0V
Time
Since the IM3533and IM3536 provide a built-in
DC bias voltage function, they can apply a DC
bias to capacitors, eliminating the need for an
external DC power supply.
Determining Cs and Cp
Generally speaking, series equivalent circuit mode is used when measuring low-impedance elements
(approximately 100Ω or less) such as high-capacitance capacitors, and parallel equivalent circuit mode is used
when measuring high-impedance elements (approximately 10 kΩ or greater) such as low-capacitance
capacitors. When the appropriate equivalent circuit mode is unclear, for example when measuring a sample
with an impedance from approximately 100Ω to 10 kΩ, check with the component’s manufacturer.
6
Tantalum capacitors
Tantalum capacitors are a type of electrolytic capacitor that uses the metal tantalum for the anode. They provide
higher capacitance in a smaller package than other types of capacitors, and they offer better voltage and
temperature characteristics than high-capacitance ceramic capacitors.
Setting example of measurement conditions
Parameters
Frequency
DC bias
Signal level
Measurement range
Speed
LowZ mode
Cs-D (120Hz), Rs(100kHz)
120Hz, 100kHz
OFF
0.5Vrms
AUTO
SLOW2
ON
*Otherwise, default settings are used.
*The above settings apply to an example measurement. Since optimal conditions vary with the measurement target, specific settings
should be determined by the instrument operator.
Surface mount fixed tantalum electrolytic capacitors with manganese dioxide solid electrolyte (IEC 60384-3)
(JIS C5101-3)
Parameters
C,D(tanδ)
Rs(ESR), Z
Rated capacitance
Rated voltage
All
All
All
All
Measurement frequency Measurement voltage*1
100Hz or 120Hz
100kHz
0.5Vrms or less
0.5Vrms or less
DC bias *2
0.7V to 1.0V
0.7V to 1.0V
Fixed tantalum capacitors with non-solid electrolyte and foil electrode(IEC 60384-15)(JIS C5101-15)
Parameters
Rated voltage
Rated capacitance
C,D(tanδ)
All
Rs(ESR)
Z
All
Measurement frequency
Measurement voltage*1
DC bias *2
100Hz or 120Hz
0.1Vp to 1.0Vp
2.1V to 2.5V *3
0.1Vp to 1.0Vp
2.1V to 2.5V *4
Choose the frequency that yields the lowest
impedance value from the following: 100 Hz,
120 Hz, 1 kHz, 10 kHz, 100 kHz, 1 MHz.
Surface mount fixed tantalum electrolytic capacitors with conductive polymer solid electrolyte(IEC 60384-24)
(JIS C5101-24)
Rated capacitance
Parameters
C,D(tanδ)
All
Rs(ESR),Z
All
Rated voltage
2.5V or less
2.5V or greater
All
Measurement frequency Measurement voltage*1
100Hz or 120Hz
0.5Vrms or less
100kHz
0.5Vrms or less
DC bias *2
1.1V to 1.5V
1.5V to 2.0V
OFF
*1 The measurement voltage (i.e., the voltage applied to the sample) is the voltage obtained by dividing the open-terminal voltage by the
output resistance and the sample.
*1 The measurement voltage (i.e., the voltage applied to the sample) can be calculated based on the open-terminal voltage, the output
resistance, and the sample’s impedance.
*2 DC bias need not be applied.
*3 DC bias need not be applied to bipolar capacitors.
*4 Apply only when using a measurement voltage of 0.5 Vp or greater.
Determining Cs and Cp
Generally speaking, series equivalent circuit mode is used when measuring low-impedance elements
(approximately 100Ω or less) such as high-capacitance capacitors, and parallel equivalent circuit mode is used
when measuring high-impedance elements (approximately 10 kΩ or greater) such as low-capacitance
capacitors. When the appropriate equivalent circuit mode is unclear, for example when measuring a sample with
an impedance from approximately 100Ω to 10 kΩ, check with the component’s manufacturer.
Products used
Mass Production Applications
Model
Measurement frequency
Features
IM3523
DC, 40Hz to 200kHz Measurement time: 2ms, high cost performance
IM3533
DC, 1mHz to 200kHz Internal DC bias function, touch panel
Research and Development Applications
Model
Measurement frequency
Features
Frequency
sweep
with
analyzer
mode
IM3570
DC, 4Hz to 5MHz
Optional equivalent cuircuit analysis firmware for the IM3570
IM9000
IM3590
DC, 1mHz to 200kHz
*For more information, plese see the product catalog.
Can measure ESR and ESL separately with its equivalent circuit analysis
function.
7
Four terminal method
When shielding is connected close to the sample Zx, the measurement current I will return via the shielding. Because the
magnetic flux generated by the current returning through the shielding negates the magnetic flux generated by the
measurement current I, this technique is especially useful as a way to reduce measurement error during low-impedance
measurement (IM35xx).
Hc
Hp
Connect all 4 wires to each shield and come as close to the DUT as possible Lp
Lc
Four terminal method
Continuous measurement mode
The IM35xx series’ continuous measurement mode can be used to make continuous measurements while varying settings
(frequency and level). In the following example, continuous Cs-D (120 Hz) and ESR (100 kHz) measurements are
performed:
Save the 120 Hz and 100 kHz measurement condition panels.
Make the measurements together in
continuous measurement mode
8
Conductive polymer capacitors
Conductive polymer capacitors have lower ESR (see below) than aluminum electrolytic capacitors and are
characterized by greater stability with regard to temperature variations. In addition, they offer excellent stability
of capacitance relative to DC bias. Measurement conditions are defined by IEC standards 60384-25-1 and
include measurements of equivalent series resistance (ESR) and the tangent D (tanδ) of the loss angle.
Setting example of measurement conditions
Parameters
Frequency
DC bias
Signal level
Measurement range
Speed
LowZ mode
Cs-D (120Hz), Rs (100kHz)
120Hz, 100kHz
ON 1.5V
0.5Vrms
AUTO
SLOW2
ON
*Otherwise, default settings are used.
*The above settings apply to an example measurement. Since optimal conditions vary with the measurement target,
specific settings should be determined by the instrument operator.
IEC 60384-25-1 Surface mount fixed aluminium electrolytic capacitors with conductive
polymer solid electrolyte
Parameters
Rated capacitance
All
C,D(tanδ)
Rs(ESR)
All
Rated voltage
2.5V or less
2.5V or more
All
Measurement frequency Measurement voltage*1
120Hz
0.5Vrms or less
100kHz±10kHz
0.5Vrms or less
DC bias *2
1.1 to 1.5V
1.5 to 2.0V
OFF
*1 The measurement voltage (i.e., the voltage applied to the sample) is the voltage obtained by dividing the open-terminal
voltage by the output resistance and the sample.
*1 The measurement voltage (i.e., the voltage applied to the sample) can be calculated based on the open-terminal
voltage, the output resistance, and the sample’s impedance.
*2 DC bias need not be applied.
Low impedance high accuracy mode
In low impedance high accuracy mode, the instrument’s output resistance is reduced, and the measurement
current is applied repeatedly for increased measurement precision. When measuring a capacitor with a high
capacitance of greater than 100µF (and therefore low impedance), low-impedance high-precision mode yields
more stable measurement. The graph below compares repeatability when using the IM3570 to make
measurements with low-impedance high-precision mode enabled and disabled (100kHz, 1Ω range, 1V).
*The conditions under which low-impedance high-precision mode can be enabled vary with the instrument
model. Please refer to the user’s manual of the instrument you are using.
0.1005 LowZ High Precision Model:OFF LowZ High Precision Model:ON Z[Ω]
0.1004 0.1003 0.1002 0
20
40
60
80
100
Number of .mes Repeated measurement of a resistance of approximately 100 mΩ with the IM3570
9
Products used
Mass Production Applications
Model
Measurement frequency
Features
IM3523
DC, 40Hz to 200kHz Measurement time: 2ms, high cost performance
IM3533
DC, 1mHz to 200kHz Internal DC bias function, touch panel
Research and Development Applications
Model
Measurement frequency
Features
Frequency
sweep
with
analyzer
mode
IM3570
DC, 4Hz to 5MHz
IM9000
Optional equivalent cuircuit analysis firmware for the IM3570
IM3590
DC, 1mHz to 200kHz
Can measure ESR and ESL separately with its equivalent
circuit analysis function.
Equivalent circuit analysis function
The instrument’s equivalent circuit analysis function can be used to analyze the L, C, and R elements that
make up the component separately. In the following figure, a conductive polymer capacitor’s ESR and ESL are
measured using the IM3570 and IM9000:
ESL & ESR
Equivalent circuit of conductive polymer capacitors
10
Continuous measurement mode
The IM35xx series’ continuous measurement mode can be used to make continuous measurements while
varying settings (frequency and level). In the following example, continuous Cs-D (120 Hz) and ESR (100 kHz)
measurements are performed:
Save the 120 Hz and 100 kHz measurement condition panels.
Make the measurements together in
continuous measurement mode.
Inductors (Coils)
Coils may be coreless (having an air core or a core made of a non-magnetic metal), or they may
have a core made of a magnetic metal (i.e., a metal with high magnetic permeability) such as ferrite.
Inductors with cores exhibit current dependence.
Setting example of measurement conditions
Parameters
Frequency
DC bias
Signal level
Measurement range
Speed
LowZ mode
Ls,Q,Rdc
Self-resonant frequency or less
OFF (cannot measure when setting ON)
CC (constant current) mode, rated current or less
AUTO
SLOW2
OFF
*Otherwise, default settings are used.
*The above settings apply to an example measurement. Since optimal conditions vary with the measurement target,
specific settings should be determined by the instrument operator.
The phenomenon of LC resonance with the coil’s (inductor’s)
inductance and parasitic capacitance is known as selfresonance. The frequency at which self-resonance occurs is
known as the self-resonant frequency. When evaluating coils,
be sure to measure L and Q at a frequency that is sufficiently
lower than the self-resonant frequency.
A coil’s inductance, which increases with frequency, can be
calculated using the following equation: Z=j2πfL. To measure
inductance efficiently while varying the frequency, set the
measurement range to AUTO. To measure with a higher degree
of precision, set the frequency to produce an impedance that
can be measured with a high-accuracy range.
Inductance [H]
Setting the measurement frequency
Frequency region in which
L and Q are measured
Self-resonant frequency
Frequency [Hz]
Frequency characteristics of the inductance
Setting the measurement signal level
When measuring a coil that exhibits current dependence (i.e., a
coil with a magnetic core), set the instrument to a signal level
such that the magnetic core is not saturated. When measuring a
coil that does not exhibit current dependence, it is
recommended to set the instrument to the signal level with the
best accuracy. With the IM35xx series, the best accuracy is
achieved with the V mode’s 1 V setting. With the IM758x series,
the measurement signal level is defined for the power when
using the DUT port’s 50 Ω termination, and the setting with the
best accuracy is +1 dBm.
When measuring a coil with a core or a coil with a low rated
current, the IM35xx series’ CC (constant current) mode is
convenient. The measurement current is controlled in software
so that it remains constant.
Frequency region in which
L and Q are measured
Inductance [H]
The measurement current can be calculated from the openterminal voltage, the instrument’s output impedance, and the
measurement target’s impedance. Set the measurement
voltage so that the rated current is not exceeded.
When current flows, the magnetic
material becomes saturated,
causing inductance to decrease.
Measurement Current [A]
Current dependence of the inductance
12
Products used
Mass Production Applications
Model
Measurement frequency
Features
Temperature correction function of Rdc
IM3533
DC,40Hz to 200kHz
Standard model,high-speed,highly stable, cost-effective analyzer
IM3536
DC,4Hz to 8MHz
High-speed measurement of coils for high frequency
IM7581
100kHz to 300MHz
Research and Development Applications
Model
Measurement frequency
Features
IM3570
DC,4Hz to 5MHz
Frequency sweep with analyzer mode
*For more information, plese see the product catalog.
Selecting Parameter, Ls or Lp
Rp
Impedance according to frequency (when D is sufficiently small)
10Hz
1kHz
100kHz 5MHz 300MHz
100mH
6.3Ω
630Ω
63kΩ
3.1MΩ
10mH 630mΩ
63Ω
6.3kΩ
310kΩ
XL
1mH
63mΩ
6.3Ω
630Ω
31kΩ
Rs
100uH 6.3mΩ 630mΩ
63Ω
3.1kΩ
10uH
63mΩ
6.3Ω
310Ω
Equivalent cuircuit of inductors
1uH
6.3mΩ 630mΩ
31Ω
1.9kΩ
*Low-inductance coils
100nH
63mΩ
3.1Ω
190Ω
10nH
6.3mΩ 310mΩ
19Ω
Rp can be ignored since impedance is low.
Select series equivalent circuit modes.
1nH
1.9Ω
Choose Lp
Depends on the case
Choose Ls
*High-inductance coils
Rs can be ignored since impedance is
high.Select series equivalent circuit modes.
Generally speaking, series equivalent circuit mode is used when measuring low-impedance elements
(approximately 100Ω or less), and parallel equivalent circuit mode is used when measuring high-impedance
elements (approximately 10 kΩ or greater). When the appropriate equivalent circuit mode is unclear, for
example when measuring a sample with an impedance from approximately 100Ω to 10 kΩ, check with the
component’s manufacturer.
An inductor will behave as though the winding’s copper loss Rs and the core loss Rp have been connected to
an ideal inductor L. An ideal coil’s inductance can be calculated as follows: XL=j2πfL. Although no general
formulation is possible since it varies with the magnitude of Rs and Rp, low-inductance coils are characterized
by a small XL, allowing the impedance when Rp and L are placed in parallel to be treated as roughly equivalent
to XL. Rs can be ignored since Ls is small, so the series equivalent circuit is used. By contrast, when the
impedance is high, Rp cannot be ignored but Rs can, so the setup can be treated as a parallel equivalent
circuit.
13
The Current flowing to the coil
The current flowing to the coil can be calculated based on the open-terminal voltage, the instrument’s output
impedance, and the measurement target’s impedance.
|Z|=√(〖〖(R〗_out+R_coil)〗^2+
〖(2πfL)〗^2 )
R_out:Output resistance
of coil |I|=|V|/|Z| L:Inductance of coil
Open circuit voltage(V)
Current (I)
Output Output
Impedance Impeadance
*1
Hc
Hp
Lc
DUT
Current detecting
circuit
Lp
voltage detecting circuit
Current flowing to DUT
*1 The output impedance varies depending on the model and on whether low-impedance high-precision
mode has been enabled. Please refer to the product specifications in the instruction manual.
Measuring Rdc
In coil evaluation, L, Q, and Rdc are measured.
Instruments such as the IM3533 and IM3536 can
measure L, Q, and Rdc without the need to use any
other devices. After measuring L and Q with an AC
signal, measure Rdc with a DC signal.
*Rs and Rp are not equal to Rdc. Rs and Rp are
resistance values that are measured with an AC signal.
They include components such as coil loss and winding
resistance, which increases due to conductor skin effects
and proximity effects.
When the winding material has a large temperature
coefficient, Rdc will vary with temperature. The IM3533
has temperature correction functionality for Rdc.
Trigger
Measurement signals
AC measurement (L,Q)
DC measurement (Rdc)
Measurement signals
14
DC superposition characteristics
Inductance [H]
Coil characteristics include DC superposition characteristics,
which indicate the extent to which inductance decreases relative
to DC current, an important evaluation item for coils that will be
used in circuits such as power supply circuits that handle large
currents.
The DC bias voltage application function built into Hioki LCR
meters is designed for use in measuring capacitors, and it
cannot be used to apply a DC current. To superpose a DC
signal, either use the DC Bias Current Unit 9269 (or 9269-10)
and an external power supply, or create your own circuit for the
purpose.
DC bias current [A]
DC superposition characteristics of L
Setting the delay time
Trigger signal
Trigger
delay
Generation circuit
Data acquisition switching
Adjust
delay
DC measurement after
AC measurement
Trigger synchronous
output:OFF
DC adjustment:ON
Generation circuit
switching
DC
delay
Data acquisition
(DC adjustment)
Data acquisition
(Rdc measurement)
Example of measurement timing (IM3536)
To reduce measurement error during Rdc measurement,
Hioki LCR meters cycle the generated voltage on and off
Voltage
to cancel the internal offset (DC adjustment function).
When the voltage being applied to the inductor changes,
the output resistance and inductor’s equivalent series
resistance and inductance cause transient phenomena.
Set a sufficiently long delay time during Rdc
measurement to ensure that the measurement results
are not affected by these phenomena. The name given
to the delay time setting varies by model, as does
measurement timing. For more information, please see
the instruction manual for the model you intend to use.
Set a sufficiently long delay time not to
be affected by transient phenomena.
Generated voltage
Time
Voltage at both
ends of inductors
Transient phenomena of inductors
If you are unsure of the appropriate delay time, first set
as long a delay time as possible. Then gradually shorten
the delay time while verifying that measured values do
not exhibit any variability.
15
Electric Transformers
AC voltages can be stepped up or down using a transformer. In terms of their basic structure, transformers
consist of primary and secondary windings around an iron core.
When current flows, a magnetic field is generated inside the windings, creating a voltage. The size of this
voltage is proportional to the number of turns. For example, a primary winding (on the input side of the
transformer) with 100 turns and a secondary winding (on the output side of the transformer) with 200 turns
would step up an input voltage of 100 V to an output voltage of 200 V since the number of output turns is twice
the number of input turns. Note that there is no change in power between the primary and secondary sides of
the transformer.
V_2/V_1 =I_1/I_2 =N_2/N_1 Setting example of measurement conditions
Parameters
Frequency
DC bias
Signal level
Measurement range
Speed
LowZ mode
Ls,Q,Rdc
Self-resonant frequency or less *1
OFF(ON is NOT applicable)
Rated current or less *1
AUTO
SLOW2
OFF
※1 Cf. Inductors Application note
*Otherwise, default settings are used.
*The above settings apply to an example measurement. Since optimal conditions vary with the measurement target,
specific settings should be determined by the instrument operator.
C
R1
R1: Primary winding resistance
R2
R2: Secondary winding resistance
C1: Primary winding floating capacity
C1
L1
M
R1: 1次巻線抵抗
C1: 1次巻線浮遊容量
L2
C2
C2: Secondary winding floating capacity
R2: 2次巻線抵抗
The Parameter for each electric transformer
C2: 2次巻線浮遊容量
The transformer is an application of an inductor, and measurement methods are the same as for
other inductors. Transformer measurement includes the following principal evaluation parameters:
・ Primary inductance (L1) and secondary inductance (L2)
・ Leakage inductance
・ Capacitance between windings ©
・ Mutual inductance (M)
・ Turn ratio
16
Products used
Mass Production Applications
Model
Frequency
Features
Temperature correction function of Rdc,transformertesting mode
IM3533
DC,40Hz to 200kHz
IM3533+ Frequency sweep
IM3533-01
DC,40Hz to 200kHz
Standard model, high-speed, highly stable, cost-effective analyzer
IM3536
DC,4Hz to 8MHz
Research and Development Applications
Model
Frequency
Features
IM3570
DC,4Hz to 5MHz
Frequency sweep with analyzer mode
*For more information, plese see the product catalog.
Primary inductance (L1) and secondary inductance (L2)
Hc
As shown in the figure to the right, a measuring
instrument can be connected directly to the
primary or secondary side of the transformer to
measure the primary or secondary inductor.
However, all other windings must be left in the
open state. Exercise care as inductance
measurement results include the effects of the
winding’s distributed capacitance.
Hp
R
C
open 開放
L
Lp
Lc
Measuring circuit for primary and secondary inductance Leakage inductance
1次巻線
(Primary
winding)
Hc
2次巻線
(Secondary
winding)
Φ12
Hp
主磁束 (Main flux)
Φσ1
Φσ2
short 短絡
Lp
漏れ磁束
(Leakage flux)
Lc
Φ21
Measuring circuit for leakage inductance
Leakage flux
In an ideal transformer, shorting output causes input to be shorted as well. However, in an actual
transformer, leakage inductance remains even when output is shorted. As shown in the above figure,
the leakage inductance can be determined by shorting the secondary side of the transformer and
measuring the primary side’s inductance.
17
What is leakage inductance?
The magnetic flux that links the transformer’s primary and secondary windings is known as the main
magnetic flux (φ12 or φ21). Apart from the main magnetic flux, the transformer’s magnetic flux also
includes primary leakage flux (φs1) , which links the primary winding but not the secondary winding,
and secondary leakage flux (φs2), which links the secondary winding but not the primary winding.
Although only the main magnetic flux exists in an ideal transformer, actual transformers always have
magnetic leakage, and therefore leakage flux. Since this leakage flux does not link only the primary
and secondary windings, it does not contribute to the transformer’s voltage-modifying operation. At
the same time, the fact that the leakage flux does not link only the primary and secondary windings
also means that it contributes as each winding’s inductance. In this way, the primary leakage flux acts
as the primary leakage inductance, and the secondary leakage flux acts as the secondary leakage
inductance.
Capacitance between windings
Hc
As shown in the figure to the right, the winding capacitance
between the primary and secondary sides of the transformer
can be measured by connecting each winding to the measuring
instrument.
Hp
Lp
Lc
開放
Open Measuring circuit for capacitance between windings
Mutual inductance
The mutual inductance can be calculated by measuring the inductance in parallel while in phase and
then in series out of phase and then using the equation shown below.
M=(La-Lo)/4
Hc
Hc
Hp
Hp
Lp
Lp
Lc
Lc
L measurement
Measuring circuit for mutual inductance
between coils
Lo measurement
18
Turn ratio
As shown in the figure to the right, the
turn ratio can be approximated by
measuring the impedance value Z on the
primary side of the transformer after
connecting the resistance R to the
secondary side.
Hc
N1
N2
Hp
R
Lp
Lc
Measuring circuit for turn ra7o of windings In addition, the turn ratio can be calculated by measuring the primary inductance L1 and the secondary
inductance L2. However, the value will only be an approximation due to the effects of factors such as magnetic
leakage.
Hc
N1
N1
N2
Hc
N2
Hp
Hp
L1
L2
L1
L2
Lp
Lp
Lc
L1 measurement
L2 measurement
Lc
Measuring circuit for turn ra7o of windings The LCR Meter IM3533/IM3533-01’s transformer measurement functionality can be used to calculate the
mutual inductance, turn ratio, and inductance difference.
Turn ratio measurement with the IM3533/IM3533-01 involves measuring the primary and secondary inductance
values and then calculating the turn ratio.
19
RFID (Contactless IC cards, Contactless IC tags)
The operating frequencies of RFIDs, which are also known as IC tags or contactless IC cards, are defined by
standards. When performing L measurement of a board used by a contactless IC card, the measurement must
be made near the operating frequency of 13.56 MHz.
Setting example of measurement conditions
Measurement mode
Parameters
Sweep parameter
Sweep frequency
Signal level
ANALYZER
Z-θ frequency characteristics analysis(L-Q、R evaluation available)
FREQ
Sweep measurement close to the operating frequency (See the table below)
V mode 1V (350x, IM35xx series) or 1dBm (IM758x series)
*The above settings apply to an example measurement. Since optimal conditions vary with the measurement target,
specific settings should be determined by the instrument operator.
RFID standards
Category
Frequency
Effective distance
Standard
ID cards
13.56MHz
Up to 10cm
(Proximity applications)
ISO14443
Automatic recognition
125kHz
13.56MHz
ISO14443
Up to 70cm (Vicinity
applications)
ISO15693
Structure of RFID tag
RFIDs generally consist of an antenna and IC. Signal transmission is accomplished by a resonant circuit
formed by the antenna inductor (Ls) and the IC chip’s built-in input capacitance (Cp).
Inductor
IC chip
Loop antenna
Circuit model
Frequency characteristics of defective and non-defective components
As shown in the following figures, the Z-θ frequency characteristics of defective and non-defective
components differ. The non-defective component exhibits a resonance point near the operating frequency.
Z[kΩ]
PHASE[deg]
Missing capacitor
Short in coil
Braking coil wire
PASS
Missing C
Short in coil
Braking coil
PASS
Frequency f[MHz]
Frequency f[MHz]
Frequency characteristics of impedance
Frequency characteristics of phase
20
Products used
Production line and R&D applications
Model
IM758x series
IM3570
Measurement frequency
RFID
100k to 1.3GHz *
Mainly for high-frequency RFID
4Hz to 5MHz
Mainly for low-frequwncy to midium frequency RFID
*For more information, plese see the product catalog.
Pass/fail judgments using analyzer mode
Either of two methods can be used to generate pass/fail judgments when using analyzer mode: peak
judgment and area judgment.
Judgement area
Judgement area
Judgement method: Whether the resonance
points fall inside a judgement area.
Judgement method: Whether all measured values
fall inside a judgement area.
Peak judgement
Area judgement
PASS
FAIL
Judgement areas can be set as follows.
• A known-good element’s measured value can be used as the
reference (±10% of the reference element’s measured value, etc.).
• A user-specified value can be entered (1 k±10%, etc.).
21
Ascertaining electrical constants by means of equivalent circuit analysis
The instrument’s equivalent circuit analysis function can be used to calculate the constants in a three-terminal
circuit model such as an RFID antenna.
*Model A should be used for coils with a large core loss (R) in order to facilitate more accurate analysis.
Equivalent circuit of an antenna
Equivalent circuit analysis result
A
B
Equivalent circuit models
C
D
E
22
Piezoelectric elements
Piezoelectric elements are used in a wide range of applications, including buzzers, sensors, and
filters. Since resonant and antiresonant frequencies characterize their impedance/frequency
characteristics, an impedance analyzer is the ideal instrument for use in analyzing their
characteristics.
Setting example of measurement conditions
Measurement modes
Parameters
Sweep parameter
Sweep frequency
Signal level
Equivalent cuicuit model
ANALYZER
Z-θ
FREQ
Set to a range within which the resonant, antiresonant frequency can be checked.
Depends on the measurement items
E
*The above settings apply to an example measurement. Since optimal conditions vary with the measurement target,
specific settings should be determined by the instrument operator.
Equivalent circuit of piezoelectric elements
Close to its resonant frequency, a piezoelectric element can
be depicted as an electrical equivalent circuit. Specifically,
such an element can be depicted as a parallel capacitance
CO that is connected in parallel to a series circuit consisting
of the series inductance L1, the series capacitance C1, and
the series resistance R1.
The following describes actual measurement and analysis
with an IM3570 and IM9000 (optional equivalent circuit
analysis software).
Equivalent cuicuit model of
piezoelectric elements
Equivalent circuit analysis results
Frequency sweep results
Products used
Model
IM3590
IM3570
IM9000
IM7581
Frequency
DC,1mHz to 200kHz
DC,4Hz to 5MHz
100kHz to 300MHz
Features
Analyzer mode (low frequency), equivalent cuircuit analysis
Frequency sweep with analyzer mode
Optional equivalent cuircuit analysis firmware for the IM3570
Analyzer mode (high frequency), equivalent cuircuit analysis
*For more information, plese see the product catalog.
23
Measuring resonant frequency and antiresonant frequency
The frequency fm characterized by minimum inductance and the frequency fn characterized by maximum
inductance can be calculated from the element’s impedance/frequency characteristics using the instrument’s
peak search function. In addition, it is possible to calculate the resonant frequency fr, which is characterized by
a phase of 0, and the antiresonant frequency fa.
The series resonant frequency fs and the parallel resonant frequency fp can be expressed as follows:
fs=​1/2𝜋√⁠𝐿1𝐶1 f𝑝=​1/2𝜋√⁠𝐿1・​C0C1/
(C0+C1) fs is the frequency when the conductance G reaches its maximum, and fp is the frequency when the actual resistance Rs
reaches is maximum. These can be calculated from C0, L1 and C1 obtained via equivalent circuit analysis.
Anti-resonance frequency fa
phase Resonance frequency fr
Frequancy [Hz]
Frequency of
minimum
inductance fm
Frequency sweep (parameter:Z-θ)
Series resonance frequency fs
Frequancy [Hz]
Frequency sweep (parameter: Y-G)
Parallel resonance frequency
fp
Frequency of
maximum
inductance fm
Frequancy [Hz]
Frequency sweep (parameter:Z-­‐Rs) 24
Pass/fail judgments using analyzer mode
Either of two methods can be used to generate pass/fail judgments when using analyzer mode: peak judgment
and area judgment.
Judgement area
Judgement results
(The resonance points fall
inside a judgement area)
Peak judgement
Judgement
area
Judgement results
(All measured values fall
inside a judgement area)
Judgement areas can be set as follows.
• A known-good element’s measured value can be used as the
reference (±10% of the reference element’s measured value, etc.).
• A user-specified value can be entered (1 k±10%, etc.).
Area judgement
25
Note: Company names and Product names appearing in this catalog are trademarks or registered trademarks of various companies.
HIOKI (Shanghai) SALES & TRADING CO., LTD.
TEL +86-21-63910090 FAX +86-21-63910360
http://www.hioki.cn / E-mail: info@hioki.com.cn
DISTRIBUTED BY
HIOKI INDIA PRIVATE LIMITED
TEL +91-124-6590210
HEADQUARTERS
E-mail: hioki@hioki.in
81 Koizumi, Ueda, Nagano, 386-1192, Japan
TEL +81-268-28-0562 FAX +81-268-28-0568
HIOKI SINGAPORE PTE. LTD.
http://www.hioki.com / E-mail: os-com@hioki.co.jp TEL +65-6634-7677 FAX +65-6634-7477
E-mail: info-sg@hioki.com.sg
HIOKI USA CORPORATION
HIOKI KOREA CO., LTD.
TEL +1-609-409-9109 FAX +1-609-409-9108
TEL +82-2-2183-8847 FAX +82-2-2183-3360
http://www.hiokiusa.com / E-mail: hioki@hiokiusa.com E-mail: info-kr@hioki.co.jp
All information correct as of Feb. 1, 2016. All specifications are subject to change without notice.
LCR Application Guide - E - 20160201
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