7400 Precision LCR Meter
Model B
Instruction Manual
Form 150262/A4
QuadTech, Inc., 1997
5 Clock Tower Place, 210 East
Maynard, Massachusetts, U.S.A. 01754
January, 2002
Telephone 978-461-2100
Sales 800-253-1230
Facsimile 978-461-4295
Website www.quadtech.com
The material in this manual is for informational purposes only and is subject to change,
without notice. QuadTech assumes no responsibility for any error or for consequential
damages that may result from the misinterpretation of any procedures in this publication.
!
Product will be marked with this symbol (ISO#3684) when it is necessary for the user to
refer to the instruction manual in order to prevent injury or equipment damage.
Product marked with this symbol (IEC417) indicates presence of direct current.
Page 2 of 118
Contents
Warranty ...........................................................................................................7
Specifications ...........................................................................................................9
Introduction - Section 1
1.1 Unpacking and Inspection.............................................................................13
1.2 Product Overview..........................................................................................13
1.3 Controls and Indicators.................................................................................. 14
1.4 Accessories Included.....................................................................................17
1.5 Accessories/Options Available...................................................................... 17
1.6 Installation .....................................................................................................18
1.6.1 Instrument Positioning.......................................................................18
1.6.2 Power Requirements.......................................................................... 18
1.6.3 Safety Inspection ............................................................................... 20
Operation - Section 2
2.1 General........................................................................................................... 21
2.2 Startup ........................................................................................................... 21
2.3 Connection to Device Under Test ................................................................. 21
2.4 Zeroing........................................................................................................... 22
2.5 Measurement Procedure................................................................................23
2.5.1 General...............................................................................................23
2.5.2 Default Measurement Conditions...................................................... 23
2.6 Menu Functions.............................................................................................25
2.6.1 General...............................................................................................25
2.6.2 Setup Menu........................................................................................25
2.6.2.1 Primary Parameter................................................................26
2.6.2.2 Secondary Parameter............................................................29
2.6.2.3 Frequency ............................................................................. 30
2.6.2.4 AC Test Signal .....................................................................30
2.6.2.5 DC Bias Voltage...................................................................32
2.6.2.6 Range Hold........................................................................... 34
2.6.2.7 Range Locked....................................................................... 34
2.6.2.8 Measurement Accuracy........................................................39
2.6.2.9 Measurement Delay..............................................................39
2.6.2.10 # to Average .......................................................................40
2.6.2.11 Contact Check ....................................................................40
Page 3 of 118
Contents (continued)
2.6.3 I/O Menu............................................................................................41
2.6.3.1 Display Type ........................................................................42
2.6.3.2 Nominal Value...................................................................... 45
2.6.3.3 Result Format ....................................................................... 45
2.6.3.4 Trigger..................................................................................46
2.6.3.5 Handler Interface..................................................................46
2.6.3.6 RS-232 Interface................................................................... 46
2.6.3.7 IEEE-488.2 Interface............................................................ 47
2.6.3.8 Print Results..........................................................................47
2.6.3.9 Results to Floppy.................................................................. 48
2.6.4 Analysis Menu................................................................................... 54
2.6.4.1 Binning ................................................................................. 55
2.6.4.2 Test Sequencing....................................................................60
2.6.4.3 Parameter Sweep .................................................................. 63
2.6.4.4 Median.................................................................................. 65
2.6.4.5 Distortion Detection ............................................................. 65
2.6.4.6 Load Correction....................................................................65
2.6.5 Utilities Menu.................................................................................... 67
2.6.5.1 Save Setup ............................................................................ 68
2.6.5.2 Recall Setup..........................................................................69
2.6.5.3 Setup Accuracy..................................................................... 70
2.6.5.4 Open / Short.......................................................................... 72
2.6.5.5 Lock Out............................................................................... 73
2.6.5.6 Calibration............................................................................74
2.6.5.7 Set Time/Date....................................................................... 74
2.6.5.8 Usage/Cal Date..................................................................... 75
2.6.5.9 Set Contrast ..........................................................................76
2.6.5.10 Self Test.............................................................................. 76
2.6.5.11 LCD Backlite......................................................................76
2.7 Input/Output Interface ................................................................................... 77
2.7.1 I/O Interface....................................................................................... 77
2.7.2 Parallel Interface................................................................................81
2.7.3 IEEE-488.2 Interface......................................................................... 82
2.7.3.1 Formats.................................................................................92
2.7.3.2 Sample Program for National Instruments GPIB card..........94
2.7.4 RS232 Interface.................................................................................95
2.7.5 Results to Printer ............................................................................... 96
Page 4 of 118
Contents (continued)
2.8 Operation with Accessories........................................................................... 97
2.8.1 General...............................................................................................97
2.8.2 Rack Mount Kit (7000-00)................................................................97
2.8.3 BNC Cable Set, 1 Meter (7000-01), 2 Meter (7000-02)...................97
2.8.4 Kelvin Clip Leads (7000-03).............................................................98
2.8.5 Alligator Clip Leads (7000-04).........................................................100
2.8.6 Chip Component Tweezers (7000-05) .............................................. 101
2.8.7 Low V, Axial/Radial Lead Component Test Fixture (7000-06).......102
2.8.8 Low V, Chip component Test Fixture (7000-07)..............................103
2.8.9 High Voltage Test Fixture (7000-08)................................................ 104
2.8.10 Calibration Kit (7000-09).................................................................. 105
2.8.11 Connections to 874 Type Adapters ................................................... 106
2.9 Error Messages .............................................................................................. 107
Theory Section 3
3.1 General........................................................................................................... 111
3.2 Instrument Description..................................................................................111
3.2.1 Basic I2000 Instrument Architecture ................................................111
3.2.2 7400 Instrument Module ................................................................... 112
3.2.3 I2000 Instrument Options..................................................................113
Maintenance/Calibration - Section 4
4.1 General........................................................................................................... 115
4.2 Instrument Return.......................................................................................... 115
4.3 Routine Maintenance.....................................................................................115
4.3.1 Battery Replacement .........................................................................115
4.3.2 Bias Voltage Fuse Replacement........................................................ 116
4.3.3 Resetting of Time and Date............................................................... 117
4.3.4 Loss of Display Contrast...................................................................117
4.3.5 Preventive Maintenance/Cleaning..................................................... 118
4.4 Calibration ..................................................................................................... 118
4.4.1 General............................................................................................... 118
4.4.2 Calibration Procedure........................................................................ 118
Page 5 of 118
Page 6 of 118
Warranty
QuadTech warrants that Products are free from defects in material and workmanship and,
when properly used, will perform in accordance with QuadTech's applicable published
specifications. If within one (1) year after original shipment it is found not to meet this
standard, it will be repaired, or at the option of QuadTech, replaced at no charge when
returned to a QuadTech service facility.
Changes in the Product not approved by QuadTech shall void this warranty.
QuadTech shall not be liable for any indirect, special or consequential damages,
even if notice has been given of the possibility of such damages.
This warranty is in lieu of all other warranties, expressed or implied, including, but
not limited to any implied warranty or merchantability or fitness for a particular
purpose.
SERVICE POLICY
QuadTech policy is to maintain product repair capability for a period of at least five (5)
years after original shipment and to make this capability available at the then prevailing
schedule of charges.
Page 7 of 118
Page 8 of 118
Specifications
Measurement Capacitance (Cs/Cp), Inductance (Ls/Lp), Resistance (Rs/Rp),
Parameters: Dissipation (DF) and Quality (Q) Factors, Impedance |Z|,
Admittance |Y|, Phase Angle (θ), Equivalent Series Resistance
(ESR), Conductance (Gp), Reactance (Xs), Susceptance (Bp)
Any two parameters measured and displayed simultaneously
Measurement |Z|, R, X: 000.0001 mohm to 99.99999 Mohm
Ranges: |Y|, G, B: 00000.01 µS to 9.999999 MS
C: 00000.01 fF to 9.999999 F
L: 0000.001 nH to 99.99999 H
D: .0000001 to 99.99999
Q: .0000000 to 999999.9
Phase Angle: -180.0000 to +179.9999 degrees
Delta %: -99.9999 % to +99.9999 %
Measurement Basic
Accuracy: LCR: +/- 0.5%* +/- 0.25%* +/- 0.05%*
DF: +/- 0.0050 +/- 0.0025 +/- 0.0005
* At optimum test signal levels, optimum DUT value and without calibration
uncertainty error. Instrument accuracy can be reduced from nominal specifications
when using some 7000 accessory fixtures and cables. Best accuracy requires
geometric consistency between that utilized during open/short zeroing and that
utilized on fixtures and cables during the actual measurement process. This
consistency may be especially difficult to achieve when using unshielded Kelvin clip
and tweezer type connections.
0.25 x (normal accuracy) with Load Correction implemented and
compared to user supplied standard.
In a range of 3Ω ≤ Z ≤ 80kΩ, 100mV ≤ programmed V ≤ 1V or
100mV ≤ (programmed I) x (Z) ≤ 1V
Test Frequency: 10 Hz to 500 kHz
Resolution: 0.1 Hz from 10 Hz to 10 kHz, 5 digits > 10 kHz
Accuracy: +/-(0.002% +0.02 Hz)
Measurement Speed: Basic Accuracy: 25 msec*/measurement
Enhanced Accuracy: 125 msec*/measurement
Extended Accuracy: 1 sec*/measurement
* may be longer, depending on test conditions & frequency
Ranging: Automatic or Range Hold
Note: s = series, p = parallel, ESR equivalent to Rs
Enhanced Extended
Page 9 of 118
Specifications (continued)
Source Impedance: 25Ω, 400Ω, 6.4 kΩ or 100 kΩ, measurement range dependent
Trigger: Internal (automatic) and External (via handler, RS-232 or IEEE-
488.2 interfaces)
AC Test Signal: Voltage: 20 mV to 5.0 V (open circuit) in 5 mV steps
Accuracy: +/- (5% + 1 mV) ≤ 100kHz
+/- (10% + 1 mV) > 100kHz
Current: 250 µA to 100 mA* (short circuit) in 50 µA steps
Accuracy: +/- (5% +50 µA) ≤ 100kHz
+/- (10% +50 µA) > 100kHz
* Can exceed 100 mA in some cases
Bias Voltage: Internal: 2.0 V External: 0 to 200 V
Display: LCD Graphics with adjustable contrast and back light
- Results of Dual Measurement Parameters in engineering
(7 digits) or scientific (5 digits) notation
- Deviation from Nominal of Primary Parameter
- % Deviation from Nominal of Primary Parameter
- Instrument Setting and Test Conditions
- Bin Limits and Pass/Fail Results
- Plot of Primary Measurement Parameter vs. Test Conditions
- Table of Measurement Parameters vs. Test Conditions
- Sequenced Test Results Summary
Limit Detection: 15 bins total (10 pass, 4 fail, 1 no contact)
Interfaces: IEEE-488.2, RS-232, Handler, Printer Port and 3.5" Floppy
Drive
Front Panel Four terminal (BNC) with Guard
Test Terminals:
Environmental: MIL-T-28800E, Type 3, Class 5, Style E & F.
Operating: 0 to + 50o C
Storage: - 40 to + 71o C
Humidity: < 75% for < 40o C operating
Altitude <2000m, Installation Category 1, Pollution Degree 1
Page 10 of
118
8/C
2 / C
Specifications (continued)
Mechanical: Bench mount with tilt bail
Dimensions: (w x h x d): 16 x 6 x 14in
(410 x 150 x 360mm)
Weight: 17 lbs (8kg) net, 23 lbs (10.5kg) shipping
Power Requirements: 90 to 250Vac 47 - 63 Hz 100W maximum
Other Features: Charged Capacitor Protection:
C = Capacitance in farads of the device under test
Measurement Delay programmable from 0-1000 ms in 1 ms steps
Measurement Averaging programmable from 1-1000
Median Value Mode
Open and Short Circuit Zeroing at Multiple Frequencies
Power Fail Protection (setting, results, & calibration data stored)
Storage and Recall of 25 Setups, 125/disk w/Floppy Option
Self-Test Routines at Power-up
Stored Results up to 40,000 measurements/disk w/Floppy Option
Self Accuracy Calibration and Display
Contact Check
Supplied: Instruction Manual Power Cable Calibration Certificate
Ordering Description Catalog No.
Information:
7400 Precision LCR Meter, Model B 7400
7400-CE Precision LCR Meter, Model B 7400-CE
7400A Precision LCR Meter, Model B +/-500V ext bias 7400A
7400A-CE Precision LCR Meter, Model B+/-500V ext bias 7400A-CE
7400C Precision LCR Meter, Model B charged C protection 7400C
7400C-CE Precision LCR Meter, Model B
Options & Accessories:
Rack Mount Kit 7000-00
BNC Cable Set, 1 meter 7000-01
BNC Cable Set, 2 meters 7000-02
Kelvin Clip Leads 7000-03
Alligator Clip Leads 7000-04
Chip Component Tweezers 7000-05
Low Voltage Axial/Radial Lead Component Test Fixture 7000-06
Low Voltage Chip Component Test Fixture 7000-07
High Voltage Test Fixture 7000-08
Calibration Kit 7000-09
for Vmax ≤ 250 V
for Vmax ≤ 1000V
charged C prot.
7400C-CE
Page 11 of
118
Section 1 Introduction
1.1 Unpacking and Inspection
Inspect the shipping carton before opening, if damaged contact the carrier’s agent
immediately. Inspect the instrument for any damage. If the instrument appears damaged
or fails to meet specifications notify QuadTech (refer to instruction manual front cover)
or its local representative. Retain the shipping carton and packing material for future use
such as returning for recalibration or service.
1.2 Product Overview
The 7400 Precision LCR Meter is an automatic, user programmable instrument for
measuring a wide variety of impedance parameters. The 7400 instrument covers a
frequency range from 10 Hz to 500 kHz with a basic measurement accuracy of 0.05%.
The instrument’s high-resolution graphics display and keypad makes for easy menu
programming. Test conditions are stored and recalled from internal memory, eliminating
wasted measurement setup time. Extensive pass/fail binning capability and
measurements speeds up to 40/sec makes the unit well suited for production applications.
The instrument's unique measurement sequencing allows up to six parameters to be
measured on a single pass. Additionally, a parameter can be plotted against a test
condition variable, an invaluable technique for component design and product evaluation.
The 7400 instrument comes with IEEE-488.2, RS-232, I/O port (handler), and parallel
interfaces, all standard, for remote control operation and communication with other
instrumentation. A 3 1/2" floppy drive is also included for program/data storage of test
conditions and measurement results.
Introduction
QuadTech
Precision
7400
LCR Meter
!
CAUTION
HIGH VOLTAGE
DISPLAY SELECT ENTRY TEST
17.52520 pF
C
.0000100
DF
Freq
Range
Delay
1.0000kHz
0 ms
AC Signal
AverageAuto
Bias
1.0000V
1
Off
12
4
7
-
MENU
3
CNCL
5
6
8
9
ENTER
.
0
Figure 1-1
7400 Precision LCR Meter
FAIL PASS
STOP
START
Page 13 of
118
23456
789
10
1.3 Controls and Indicators
Figure 1-2 shows the controls and indicators on the front panel of the 7400. Table 1-1
identifies them with descriptions and functions.
QuadTech
Precision
7400
LCR Meter
!
CAUTION
HIGH VOLTAGE
DISPLAY SELECT ENTRY TEST
17.52520 pF
C
.0000100
DF
Freq
1.0000kHz
Range
Delay
AC Signal
AverageAuto
Bias0 ms
1.0 V
1
Off
12
4
7
-
MENU
3
CNCL
5
6
8
9
ENTER
.
0
11 12 131
FAIL PASS
STOP
START
Figure 1-2
Front Panel Controls & Indicators
Table 1-1
Front Panel Controls and Indicators
Figure 1-2
Ref. No. Item Function
1 Input Panel BNC connectors, for connection to device
under test (DUT). 7/8 inch spacing.
IL Current, low connection to DUT
PL Potential, low connection to DUT
PH Potential, high connection to DUT
IH Current, high connection to DUT
2 Voltage indicator Indicates when external dc bias voltage is
called for or applied to rear panel
connectors, from external source
3 Graphics display Displays test conditions, measured results,
instrument status and user interface menus.
Page 14 of 118 Introduction
Table 1-1 (continued)
Front Panel Controls and Indicators
Figure 1-2
Ref. No. Item Function
4
Select keys (4)
Soft key functions as indicated on the
adjacent LCD display.
- from top to bottom, functions such as up,
down, right or left arrow during menu
selection.
- other functions such as measurement
units, exponent, Y or N (yes or no) and del
(delete).
5 Keypad (12) For making numerical entries as labeled,
0 through 9, minus sign and decimal.
6 CNCL key Exits an active field in vertical or
horizontal selections, clears entry on #
fields when pressed once and exits # fields
when pressed twice.
7 MENU key Enters menu display mode or exits sub
menu back to main menu.
8
ENTER key
Switches user to entry mode or accepts
menu entry as entered.
9
Pass/Fail indicator
Indicates measurement results based on
entered test limits.
10 STOP key Stops the measurement process.
11 START key Starts the measurement process.
12
Power switch
Turns main power to instrument on or off.
13
Floppy drive
For storing measurement setup conditions
and measurement results. A high density
(1.44M) or low density (720K) DOS 3.5"
compatible floppy drive. Floppies should
be double sided, formatted for DOS
compatibility.
Introduction
Page 15 of
118
1
23456
7
+
BIAS VOLTAGE
200V MAX
BATTERY
-
90 - 250 V
47 - 63 Hz
100 WATTS MAX
IEEE-488 INTERFACE
PARALLEL PORT RS-232 INTERFACE
I/O PORT
Figure 1-3
Rear Panel View
Table 1-2
Rear Panel Connectors and Controls
Figure 1-3
Ref. No. Item Function
1 ! AC Inlet Module AC power input, filtering, fusing and
switching. Use with Belden SPH-386
socket or equivalent. Contains T2.5A,
250V, 5x20mm time delay fuse for 115 or
120V operation. Replace only with the
same type and rating. Also refer to
paragraph 1.6.2.
2 IEEE-488.2 Input/output connections according to IEEE
STD-488.2. 24 pin socket for standard
IEEE-488 cable. Refer to paragraph 2.7.3.
3
I/O Connector
Connection to component handler. 36 pin
Amp connector, mates with Amp 552302-1
plug and 552073-5 strain relief cover or
ribbon cable clamp connector 553600-1 or
equivalents. Refer to paragraph 2.7.1
4 Parallel Port Connection to parallel printer. Type
DB25 (25 pin) female connector. Refer to
paragraph 2.7.2.
5
RS232 Connector
Connection according to RS232 std
interface. Type DB9 (9 pin) male
connector. Refer to paragraph 2.7.4.
Page 16 of 118 Introduction
Table 1-2 (continued)
Rear Panel Connectors and Controls
Figure 1-3
Ref. No. Item Function
6 ! Bias Voltage External bias input, maximum of
+/-200Vdc. Contains F0.25A, 250V,
5x20mm fast blow fuse. Replace only with
the same type and rating. Also refer to
paragraph 2.6.2.5.
7
Battery
DC source for backup of system memory,
3 standard alkaline AA batteries which
should be replaced annually (Refer to
paragraph 4.3.1)
1.4 Accessories Included
Table 1-3
Item Quantity
Instruction Manual 1
Calibration Certificate 1
Power Cord (CE units with international cord set) 1
Fuse (T2.5A, 250V, 5x20mm, for 115/120V operation) 1
1.5 Accessories/Options Available
Table 1-4
Item Part Number
Rack Mount Kit 7000-00
BNC Cable Set, 1 meter 7000-01
BNC Cable Set, 2 meters 7000-02
Kelvin Clip Leads 7000-03
Alligator Clip Leads 7000-04
Clip Component Tweezers 7000-05
Low Voltage Axial/Radial Lead Component Test Fixture 7000-06
Low Voltage Chip Component Test Fixture 7000-07
High Voltage Test Fixture 7000-08
Calibration Kit 7000-09
Introduction
Page 17 of
118
1.6 Installation
1.6.1 Instrument Positioning
The 7400 contains a high resolution back lit LCD for convenient viewing. The optimum
angle for viewing is straight onto the display. This means that for bench operation the
front bail should sometimes be used to angle the instrument up and for rack installation it
should be mounted somewhat at eye level.
1.6.2 Power Requirements
!
The 7400 Precision LCR Meter can be operated from a power source between 90
and 250Vac at a power line frequency of 47 to 63Hz, no line voltage switching is
necessary. Power connection to the rear panel is through an ac inlet module comprised of
an ac connector and fuse drawer. Before connecting the 3-wire power cord between the
unit and AC power the fuse should be in accordance with the power source, T2.5A,
250V, 5x20mm (QuadTech PN 520049) for 115 or 120V source. Always use an outlet
that has a properly connected protection ground. The 7400 unit is factory shipped with
the 2.5A fuse in place. The instrument can be damaged if the wrong fuse is
installed.
MAKE SURE THE UNIT HAS BEEN DISCONNECTED FROM ITS AC POWER
To change the fuse proceed as follows:
WARNING
SOURCE FOR AT LEAST FIVE MINUTES BEFORE PROCEEDING.
Fuse drawer with release tab
+
BIAS VOLTAGE
200V MAX
BATTERY
-
IEEE-488 INTERFACE
PARALLEL PORT RS-232 INTERFACE
I/O PORT
90 - 250 V
47 - 63 Hz
100 WATTS MAX
Figure 1-4
Fuse Drawer
Page 18 of 118 Introduction
Spare fus
Contacts
Remove the fuse drawer by inserting a small flat head screwdriver behind the small
•
tab to force the draw outward. Refer to Figure 1-4.
•
Once the fuse draw has been completely removed from the instrument remove the
clear fuse tray from the drawer by lifting upward slightly on the long narrow black
locking tab. This will allow the fuse tray to be removed from the fuse draw. This
tray contains the active fuse, left side (secured by holder) and spare fuse on the right
side (if present). Refer to Figure 1-5.
• Remove the active fuse from the holder by prying upward using a small flat head
screwdriver. Insert the replacement fuse into the fuse holder.
• Once the fuse has been installed in the holder and spare fuse (if desired) installed in
the right side of the tray insert the tray back into the fuse drawer, push in and lock.
The two silver contacts on the fuse tray should be positioned towards the outside.
• Once the fuse tray has been installed in the draw, reinstall the fuse draw back into the
instrument ac inlet module, push in and lock.
Active fuse in holder
this side
Locking tab
this side
Figure 1-5
Fuse Drawer
Introduction
Page 19 of
118
1.6.3 Safety Inspection
!
Before operating the instrument inspect the power inlet module on the rear of the
7400 to ensure that the properly rated fuse is in place, otherwise damage to unit is
possible. Refer to paragraph 1.6.2.
The 7400 is shipped with a standard U.S. power cord, QuadTech PN 4200-0300 (with
Belden SPH-386 socket or equivalent, and 3 wire plug conforming to IEC 320) and CE
units with an approved international cord set. Make sure the instrument is only used with
these cables (or other approved international cord set) which ensures the instrument is
provided with connection to protective earth ground.
When the 7400 is used in a rack installation (using the QuadTech 7000-00 Rack Mount
Kit) make sure the unit is secured using the cabinet mounting rails and not secured
solely by the front panel angle brackets.
In bench or rack mount applications the instrument should be positioned with
consideration for ample air flow to the rear panel fan ventilation holes. An open space
of at least 3 inches (75mm) is recommend behind the rear panel. The surrounding
environment should be
free from excessive dust
to prevent contamination of electronic
circuits.
If this instrument is used in a manner not specified in this manual
WARNING
If this instrument is used in a manner not specified in this manual protection to the
operator and equipment may be impaired.
Page 20 of 118 Introduction
Section 2 Operation
2.1 General
Once the 7400 unit is powered up it is ready immediately for testing, at default test
conditions, by pressing the START button. Power-up default conditions are discussed
in paragraph 2.5.2. Any of these conditions and all other instrument operations can be
changed by easy-to-use menu functions, for simplicity of understanding, descriptions and
uses of all these functions refer to menu discussions in paragraph 2.6. The Contents list
in the front of this manual should be used for quickly locating specific subjects of
interest.
NOTE
For optimum measurement results at specified accuracy a 30-minute instrument
warm-up period is highly recommended.
2.2 Startup
Connect the instrument power cord to the source of proper voltage. The instrument is
to be used only with three-wire grounded outlets. The proper fuse must be installed
as described in paragraph 1.6.2.
Power is applied to the 7400 by pressing the POWER button on the front panel. The
instrument runs a self-test and any error messages are displayed accordingly.
2.3 Connection to Device Under Test
The 7400 instrument employs a four terminal measurement configuration that permits
easy, accurate and stable measurements and avoids mutual inductance, interference from
measurement signals, noise and other factors inherent with other types of connections.
To help maintain measurement integrity, QuadTech makes available a number of
accessory cable sets and fixtures for connection directly to the front panel BNC
connectors. Refer to paragraph 1.5 for a list of available accessories.
Operation Page 21 of 118
DUT
7400
7400
Precision
LCR Meter
Ground
IH PH PL IL
!
CAUTION
HIGH VOLTAGE
IL IH
PL PH
+-
Figure 2-1 Figure 2-2
Panel Layout Test Lead Configuration
Figures 2-1 and 2-2 show the 7400 connector configuration and a typical four terminal
connection to the device under test. H and L on the 7400 denote polarity of AC test
signal at the measurement terminals as well as + and - polarity of DC bias voltage
when applied to the DUT. Refer to paragraph 2.8 for information on operation and
connection of QuadTech accessory cables and fixtures.
WARNING
When DC bias is applied, the PH connection carries a DC positive voltage with respect to
ground.
2.4 Zeroing
Before making measurements, the 7400 should be zeroed to correct for test lead and/or
fixture errors. During the zeroing process corrections are calculated and stored in
instrument memory and applied to subsequent measurements. Measurement accuracy is
specified at the end of the QuadTech one meter cable (7000-01). Open and short circuit
zeroing should be done at the end of this cable. In order to maintain instrument accuracy
with other cable lengths the instrument should be re calibrated using the QuadTech 700009 Calibration Kit and the alternate cable. Generally the unit should be zeroed at least
once per day and each time test leads or fixture are changed.
zero if the test frequency is changed. The zeroing routine is accessed through the
Utilities Menu as follows:
•
Press MENU key
•
Press LEFT/RIGHT ARROW to select Utilities menu
• Press UP/DOWN ARROW key for Open / Short
•
Press ENTER
It is not necessary to re-
For guarded measurements
connect to DUT shield
Page 22 of 118 Operation
Follow the instructions shown on the LCD display for open and short circuit zeroing of
test leads and/or fixture. During the Open Test the leads or fixture should be open with
no component connected. During the Short Test leads should be connected or fixture
shorted (using a clean copper wire, as short as possible). Refer to paragraph 2.6.5.4 as
necessary for more detail.
2.5 Measurement Procedure
2.5.1 General
Whenever the 7400 instrument is powered up it is ready immediately to begin
measuring at default test conditions. Initially, these conditions will be set to a factory
default but can be changed by the user and stored to overwrite factory default.
initiate a test once a device is connected press START;
the LCD display shows the
measured results and test conditions similar to the illustration of Figure 2-3. For
information on changing test conditions refer to paragraph 2-6 on Menu Functions.
NOTE
For optimum measurement results at specified accuracy a 30-minute instrument
warm-up period is highly recommended.
To
Measured Parameters
Voltage
RETST
pFCs 17.52510
DF
Freq
Range
Delay
2.5.2 Default Measurement Conditions
A set of default measurement conditions are initially established at the factory and stored
in instrument memory. Default conditions are those that determine the instruments status
on power up, thus the instrument is always set to a known state before any testing begins.
The user can change these conditions to tailor the test to a specific application. Refer to
paragraph 2.6.5.1 under Save Setup on the Utilities menu.
0.0000500
1.0000kHz
Auto
Figure 2-3
Measured Results Display
AC Signal
Average
Bias
1.000V
1
Off0 ms
Operation Page 23 of 118
Factory default measurement conditions are:
Under Setup Menu
Primary Parameter - Auto
Secondary Parameter - None
Frequency - 1 kHz
AC Test Signal - 1V
DC Bias Voltage - Off
Range Hold - Off
Range Locked - 0
Measurement Accuracy - Enhanced
Delay Time - 0
# to Average - 1
Contact Check - Off
Under I/O Menu
Display Type - Measured Parameters
Nominal Value - None
Result Format - Engineering
Trigger - External
Handler - On
RS-232 - Disable
IEEE - Disable
Print Results - Off
Results to Floppy - Off
Under Analysis Menu
Binning - None
Test Sequence - Off
Parameter Sweep - Off
Median - Off
Distort Detect - On
Load Correction - Off
Under Utilities Menu
Lockout - Off
Backlite - On
Page 24 of 118 Operation
2.6 Menu Functions
2.6.1 General
All programmable functions of the Model 7400 are controlled by easy to use menu
displays. The user enters the menu mode by selecting the MENU key that calls up four
top level menus, Setup, I/O, Analysis and Utilities. Each one of these is comprised of a
sub menu list whose functions are described in detail below. Maneuvering around the
menu listing is accomplished in a fashion similar to an Automatic Teller Machine (ATM)
using the UP, DOWN, RIGHT and LEFT arrow keys as indicated on the adjacent LCD
display. A highlighted menu function can be controlled by selecting the ENTER key,
making the desired entry or selection and pressing ENTER again to implement.
2.6.2 Setup Menu
Setup
Primary Parameter
Secondary Parameter
Frequency
AC Test Signal
DC Bias Voltage
Range Hold Off On
Range Locked = 0
Measurement Accuracy
Measurement Delay
# to Average
Contact Check
I/0 Utilities
(ms)
Analysis
= 1.0000 kHz
Off
= 0
= 1
Off
Int
On
>>
>>
>>
Ext
>>
Figure 2-4
Setup Menu
The first of the four main menus is Setup, shown above. Each function controls a 7400
measurement condition and is described in detail below.
Operation Page 25 of 118
Setup I/O Analysis Utilities
- On
Primary Parameter
Secondary Parameter
Frequency - (numeric entry)
AC Test Signal
- Voltage
- Current
- Value - (numeric entry)
DC Bias Voltage
- Off
- Int
- Ext
- OffRange Hold
- On
Range Locked - (numeric entry)
Measurement Accuracy
- Basic
- Enhanced
- Extended
Measurement Delay - (numeric entry)
# to Average - (numeric entry)
None
DF
Q
ESR
θ
Rs
Rp
Gp
Cs
Cp
Ls
Lp
|Z|
|Y|
Xs
Bp
Auto
Cs
Cp
Ls
Lp
Rs
Rp
DF
Q
|Z|
|Y|
θ
ESR
Gp
Xs
Bp
Contact Check - Off
2.6.2.1 Primary Parameter
Pri Param
Auto
Cs
Cp
Ls
Lp
Rs
Rp
DF
Q
|Z|
|Y|
(more)
HIT MENU TO RETURN TO MAIN MENU
Additional Parameters not shown may be selected by UP/DOWN arrow keys and include:
θθθθ
, ESR, Gp, Xs, Bp
I/0 UtilitiesSetup
Analysis
Figure 2-5
Primary Parameters
Page 26 of 118 Operation
Any combination of two parameters can be measured and displayed simultaneously on
the 7400, one referred to as the Primary (displayed first) and the other the Secondary.
The instrument as powered up provides a default primary parameter selection of Auto, a
feature that enables any passive component to be measured without knowing what type of
component it is. Depending on the component type the primary and secondary default
could be Cs & DF, Rs & Q, or Ls & Q. The parameter selection can be chosen by the
operator through menu selection as shown in Figure 2-5 above. In addition to Auto, the
following selections are possible and discussed in more detail below.
Cs - Capacitance in farads |Z| - Impedance magnitude in ohms
Cp - Capacitance in farads |Y| - Admittance magnitude in siemens
Ls - Inductance in henries θ - Phase angle in degrees
Lp - Inductance in henries ESR - Equivalent series resistance in ohms
Rs - Resistance in ohms Gp - Conductance in siemens
Rp - Resistance in ohms Xs - Reactance in ohms
DF- Dissipation Factor (no units) Bp - Susceptance in siemens
Q - Quality Factor (no units)
s = series equivalent circuit
p = parallel equivalent circuit
An impedance that is neither a pure resistance nor a pure reactance can be represented at
any specific frequency by either a series or a parallel combination of resistance and
reactance. Such a representation is called an equivalent circuit. The value of the primary
measurement of a device depends on which equivalent circuit, series or parallel, is chosen
to represent it. The manufacturer or user of a device specifies how a device is to be
measured (usually series) and at what frequency. If this is not known, be sure to specify
if the results were series or parallel and at what frequency.
Series and parallel equivalent circuits for a lossy inductor and lossy capacitor are shown
in Figure 2-6.
Operation Page 27 of 118
Rs
Cs
Cp
Rp or
Gp
Rs
Lp
Ls
Figure 2-6
Series and Parallel Circuits for both Capacitive and Inductive Impedances
Impedance is the parameter used to characterize electronic components, materials and
circuits. Impedance |Z| is defined as the opposition a device or circuit offers to the flow
of ac current at a particular frequency and is generally represented as a complex quantity
consisting of a real part (resistance, R) and imaginary part (reactance, jX). Impedance
can be expressed using the rectangular coordinate form (R + jX) or polar form as
magnitude and phase angle (|Z| ∠θ). Figure 2-7 shows the mathematical relationship
between R, X, |Z|, and θ for both inductive and capacitive devices. In some cases it
becomes mathematically practical to represent impedance using the reciprocal where
1/|Z| = |Y| = |G + jB|, where |Y| represents admittance, G conductance, and B
susceptance. This mathematical relationship is shown in Figure 2-8 for inductive and
capacitive devices.
+jX
Rs
+R
θ
δ
+j Ls
ω
δ
|Z|
Rp or
Gp
ω
-j/ Cs
-jX
|Z|
Impedance
-jXRs
θ
+R
InductanceCapacitance
Figure 2-7
Phasor Diagrams of Impedances
Page 28 of 118 Operation
j Cp
ω
+jB
|Y|
+jB
InductanceCapacitance
Gp
φ
+G
δ
δ
φ
+G
ω
-j/ Lp
|Y|
Gp
-jB
-jB
Admittance
Figure 2-8
Phasor Diagrams of Admittances
Quality factor (Q) is used as a measure of a reactance's purity (how close it is to being a
pure reactance, i.e. no resistance) and defined as the ratio of the energy stored in a device
to the energy dissipated by the device. Q is dimensionless and is expressed as Q = X/R =
B/G. From Figure 2-8 one can see that Q is the tangent of the angle φ. Q is commonly
applied to inductors and for capacitors the term generally used to express purity is
Dissipation Factor (D), which is the reciprocal of Q.
Any parameter, primary or secondary, can be chosen as the default parameter at power
up, refer to paragraph 2.6.5.1, changing default conditions.
2.6.2.2 Secondary Parameter
Sec Param
None
DF
Q
ESR
θθθθ
Rs
Rp
Gp
Cs
Cp
Ls
(more)
HIT MENU TO RETURN TO MAIN MENU
I/0 UtilitiesSetup
Analysis
Figure 2-9
Secondary Parameter
Operation Page 29 of 118
Additional Parameters not shown and selected by UP/DOWN arrow keys include: Lp,
|Z|, |Y|, Xs, Bp
As in the primary parameter selection, any parameter can be chosen by the operator for
display. The instrument as powered up provides a default secondary parameter. When
the default primary parameter is Auto the secondary parameter is dependent and
determined by it. If the primary default is Cs the secondary defaults to D. If the primary
default is Ls or Rs the secondary defaults to Q. The parameter selection can be chosen by
the operator through menu selection as shown in Figure 2-9.
2.6.2.3 Frequency
Numerical entry accepts up to five digits with decimal, of the desired test frequency
between 10 Hz and 500 kHz. Resolution of setting is 0.1 Hz from 10 Hz to 10 kHz and 5
digits above 10 kHz.
Units of frequency,
Hz, kHz, or MHz
are selected by the
UP/DOWN
arrow keys.
2.6.2.4 AC Test Signal
Setup
AC Signal
Signal Type
Signal Value
I/0 Utilities
Analysis
Voltage
= 1.000 V
Current
HIT MENU TO RETURN TO MAIN MENU
Figure 2-10
AC Test Signal
RIGHT/LEFT arrow keys allow selection of the AC Signal Type as either a
Voltage
source or Current source.
With Signal Type selected as Voltage, Signal Value accepts entry of a value between
.020 and 5 volts (open circuit) in 0.005 V steps.
With Signal Type selected as
Current,
Signal Value accepts entry of a value between
.00025 and .1 amp (short circuit) in .00005 amp steps.
Numerical values can be entered directly with units. Units for voltage value, mV or V
and units of current value, µµµµ
Page 30 of 118 Operation
A, mA or A are selected by the UP/DOWN arrow keys. Any
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