x
TCP0020 & TCP2020
50 MHz, 20 Amp AC/DC Current Probes
ZZZ
Instruction Manual
*P071300200*
071-3002-00
xx
TCP0020 & TCP2020
50 MHz, 20 Amp AC/DC Current Probes
ZZZ
Instruction Manual
Revision A
www.tektronix.com
071-3002-00
Copyright © Tektronix. All rights reserved. Licensed software products are owned by Tektronix or its subsidiaries or suppliers, and are protected by
national copyright laws and international treaty provisions.
Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supersedes that in all previously
published material. Specifications and price change privileges reserved.
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
Contacting Tektronix
Tektronix, Inc.
14150 SW Karl Braun Drive
P.O . Bo x 50 0
Beaverton, OR 97077
USA
For product information, sales, service, and technical support:
In North America, call 1-800-833-9200.
Worldwide, visit www.tektronix.com to find contacts in your area.
Warranty
Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one (1) year from the date of shipment. If
any such product proves defective during this warranty period, Tektronix, at its option, either will repair the defective product without charge for parts
and labor, or will provide a replacement in exchange for the defective product. Parts, modules and replacement products used by Tektronix for
warranty work may be new or reconditioned to like new performance. All replaced parts, modules and products become the property of Tektronix.
In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration of the warranty period and make
suitable arrangements for the performance of service. Customer shall be responsible for packaging and shipping the defective product to the service
center designated by Tektronix, with shipping charges prepaid. Tektronix shall pay for the return of the product to Customer if the shipment is to a
location within the country in which the Tektronix service center is located. Customer shall be responsible for paying all shipping charges, duties,
taxes, and any other charges for products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate maintenance and care. Tektronix
shall not be obligated to furnish service under this warranty a) to repair damage resulting from attempts by personnel other than Tektronix
representatives to install, repair or service the product; b) to repair damage resulting from improper use or connection to incompatible equipment; c) to
repair any damage or malfunction caused by the use of non-Tektronix supplies; or d) to service a product that has been modified or integrated with
other products when the effect of such modification or integration increases the time or difficulty of servicing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THE PRODUCT IN LIEU OF ANY OTHER WARRANTIES, EXPRESS OR
IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE. TEKTRONIX' RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY
PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY. TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY
INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS
ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.
[W2 – 15AUG04]
Table of Contents
General safety summary .................................................................................................................... v
Service safety summary.................................................................................................................... ix
Compliance Information ..................................................................................................................... x
EMC Compliance ...................................................................................................................... x
Certifications and Compliances ..................................................................................................... xii
Environmental Considerations....................................................................................................... xv
Preface.................................................................................................................................... xvii
Documentation...................................................................................................................... xvii
Conventions Used in This Manual.................................................................................................. xvii
Returning the Probe for Servicing .................................................................................................. xviii
Key Features ............................................................................................................................... 1
Installation .................................................................................................................................. 3
Degaussing the Probes .. . ............................................................................................................ 5
Controls and Indicators..................................................................................................................... 8
Probe Head ........................................................................................................................... 8
TCP0020 Probe ..................................................................................................................... 10
TCP2020 Probe...................................................................................................................... 20
Table of Contents
20 A Current Probes Instruction Manual i
Table of Contents
Functional Check .......................................................................................................................... 24
Accessories and Options.................................................................................................................. 25
Basic Operation............................................................................................................................ 32
Probing Principles ......................................................................................................................... 34
Application Examples...................................................................................................................... 47
Specifications.............................................................................................................................. 53
Standard Accessories ............................................................................................................... 26
Optional Accessories ................................................................................................................ 29
Options............................................................................................................................... 31
Degaussing a Probe with an Unpowered Conductor inthe Jaws .................................................................. 34
Measuring Differential Current....................................................................................................... 35
Extending Current Range. . .......................................................................................................... 37
Increasing Sensitivity ................................................................................................................ 40
Common Mode Noise/Magnetic Field Errors........................................................................................ 41
AC and DC Coupling.................................................................................................................42
Maximum Current Limits............................................................................................................. 43
Inductance Measurements .......................................................................................................... 48
Measuring Inductor Turns Count .................................................................................................... 51
Warranted Characteristics ........................................................................................................... 53
Typical Characteristics............................................................................................................... 54
Nominal Characteristics ............................................................................................................. 60
ii 20 A Current Probes Instruction Manual
Table of Contents
Performance Verification .................................................................................................................. 61
Equipment Required ................................................................................................................. 62
Making the DC Current Loop ........................................................................................................ 63
Equipment Setup..................................................................................................................... 64
DC Gain Accuracy ................................................................................................................... 65
Rise Time and Bandwidth ........................................................................................................... 69
TestRecord .......................................................................................................................... 71
Adjustments................................................................................................................................ 72
Prerequisites ......................................................................................................................... 72
DC Gain Accuracy ................................................................................................................... 73
Maintenance . . ............................................................................................................................. 74
Troubleshooting...................................................................................................................... 74
Cleaning.............................................................................................................................. 76
Index
20 A Current Probes Instruction Manual iii
Table of Contents
iv 20 A Current Probes Instruction Manual
General safety summary
Review the following safety precautions to avoid injury and prevent damage to this product or any products connected to it.
To avoid potential hazards, use this product only as specified.
Only qualified personnel should perform service procedures.
While using this product, you may need to access other parts of a larger system. Read the safety sections of the other component
manuals for warnings and cautions related to operating the system.
To avoid fire or personal injury
General safety summary
Use proper power cord.
Connect and disconnect properly.
source.
Connect and disconnect properly.
Connect and disconnect properly.
circuit under test. Connect the probe reference lead to the circuit under test before connecting the probe input. Disconnect the probe
input and the probe reference lead from the circuit under test before disconnecting the probe from the measurement instrument.
Ground the product.
electric shock, the grounding conductor must be connected to earth ground. Before making connections to the input or output
terminals of the product, ensure that the product is properly grounded.
Observe all terminal ratings.
manual for further ratings information before making connections to the product.
20 A Current Probes Instruction Manual v
Use only the power cord specified for this product and certified for the country of use.
Do not connect or disconnect probes or test leads while they are connected to a voltage
De-energize the circuit under test before connecting or disconnecting the current probe.
Connect the probe output to the measurement instrument before connecting the probe to the
This product is indirectly grounded through the grounding conductor of the mainframe power cord. To avoid
To avoid fire or shock hazard, observe all ratings and markings on the product. Consult the product
General safety summary
Do not connect a current probe to any wire that carries voltages above the current probe voltage rating.
Power disconnect.
accessible to the user at all times.
Do not operate without covers.
Do not operate with suspected failures.
service personnel.
Avoid exposed circuitry.
Use proper AC adapter.
The power cord disconnects the product from the power source. Do not block the power cord; it must remain
Do not operate this product with covers or panels removed.
If you suspect that there is damage to this product, have it inspected by qualified
Do not touch exposed connections and components when power is present.
Use only the AC adapter specified for this product.
Do not operate in wet/damp conditions.
Do not operate in an explosive atmosphere.
Keep product surfaces clean and dry.
vi 20 A Current Probes Instruction Manual
Terms in this manual
These terms may appear in this manual:
General safety summary
WARNING.
CAUTION.
Warning statements identify conditions or practices that could result in injury or loss of life.
Caution statements identify conditions or practices that could result in damage to this product or other property.
Symbols and terms on the product
These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you read the marking.
WARNING indicates an injury hazard not immediately accessible as you read the marking.
CAUTION indicates a hazard to property including the product.
20 A Current Probes Instruction Manual vii
General safety summary
The following symbol(s) may appear on the product:
viii 20 A Current Probes Instruction Manual
Service safety summary
Service safety summary
Only qualified personnel should perform service procedures. Read this
before performing any service procedures.
Do not service alone.
first aid and resuscitation is present.
Disconnect power.
power.
Use care when servicing with power on.
battery (if applicable), and disconnect test leads before removing protective panels, soldering, or replacing components.
To avoid electric shock, do not touch exposed connections.
Do not perform internal service or adjustments of this product unless another person capable of rendering
To avoid electric shock, switch off the instrument power, then disconnect the power cord from the mains
Dangerous voltages or currents may exist in this product. Disconnect power, remove
Service safety summary
General safety summary
and the
20 A Current Probes Instruction Manual ix
Compliance Information
Compliance Information
This section lists the EMC (electromagnetic compliance), safety, and environmental standards with which the instrument complies.
EMC Compliance
EC Declaration of Conformity – EMC (Applies Only to the TCP2020 Probe)
Meets intent of Directive 2004/108/EC for Electromagnetic Compatibility. Compliance was demonstrated to the following
specifications as listed in the Official Journal of the European Communities:
EN 61326-1 2006.
CISPR 11:2003. Radiated and conducted emissions, Group 1, Class A
IEC 61000-4-2:2001. Electrostatic discharge immunity
IEC 61000-4-3:2002. RF electromagnetic field immunity
IEC 61000-4-4:2004. Electrical fast transient / burst immunity
IEC 61000-4-5:2001. Power line surge immunity
IEC 61000-4-6:2003. Conducted RF immunity
IEC 61000-4-11:2004. Voltage dips and interruptions immunity
EN 61000-3-2:2006.
EN 61000-3-3:1995.
x 20 A Current Probes Instruction Manual
EMC requirements for electrical equipment for measurement, control, and laboratory use.
4
AC power line harmonic emissions
Voltage changes, fluctuations, and flicker
123
Compliance Information
European contact.
Tektronix UK, Ltd.
Western Peninsula
Western Road
Bracknell, RG12 1RF
United Kingdom
1
This product is intended for use in nonresidential areas only. Use in residential areas may cause electromagnetic interference.
2
Emissions which exceed the levels required by this standard may occur when this equipment is connected to a test object.
3
For compliance with the EMC standards listed here, high quality shielded interface cables should be used.
4
Performance Criterion C applied at the 70%/25 cycle Voltage-Dip and the 0%/250 cycle Voltage-Interruption test levels
(IEC 61000-4-11).
Australia / New Zealand Declaration of Conformity – EMC
Complies with the EMC provision of the Radiocommunications Act per the following standard, in accordance with ACMA:
CISPR 11:2003. Radiated and Conducted Emissions, Group 1, Class A, in accordance with EN 61326-1:2006 and
EN 61326-2-1:2006.
20 A Current Probes Instruction Manual xi
Compliance Information
Certifications and Compliances
EC Declaration of Conformity - Low Voltage
Compliance was demonstrated to the following specification as listed in the Official Journal of the European Communities:
Low Voltage Directive 2006/95/EC.
EN 61010-1:2001. Safety requirements for electrical equipment for measurement control and laboratory use.
EN 61010-2-032:2002. Particular requirements for handheld current clamps for electrical measurement and test equipment.
U.S. Nationally Recognized Testing Laboratory Listing
UL 6010B-2-032:2003. Particular requirements for handheld current clamps for electrical measurement and test equipment.
UL 61010-1 (2ndEdition)- Safety requirements for Electrical Equipment for measurement, Control, and Laboratory use - Part
1: General Requirements
Canadian Certification
CAN/CSA C22.2 No. 61010-1-04. Particular requirements for electrical equipment for measurement, control, and laboratory
use. Part 1.
CAN/CSA C22.2 No. 61010-2-032:04. Particular Requirements for Hand Held Current Clamps for Electrical Measurement
and Test.
xii 20 A Current Probes Instruction Manual
Compliance Information
Additional Compliance
IEC 61010-1:2001. Safety requirements for electrical equipment for measurement, control, and laboratory use.
IEC 61010-2-032:2002. Particular requirements for handheld current clamps for electrical measurement and test equipment.
Equipment Type
Measurement
Pollution Degree Descriptions
A measure of the contaminates that could occur in the environment around and within a product. Typically the internal environment
inside a product is considered to be the same as the external. Products should be used only in the environment for which they
are rated.
Polution Degree 1. No pollution or only dry, nonconductive pollution occurs. Products in this category are generally
encapsulated, hermetically sealed, or located in clean rooms.
Polution Degree 2. Normally only dry, nonconductive pollution occurs. Occasionally a temporary conductivity that is caused by
condensation must be expected. This location is a typical office/home environment. Temporary condensation occurs only
when the product is out of service.
20 A Current Probes Instruction Manual xiii
Compliance Information
Polution Degree 3. Conductive pollution, or dry, nonconductive pollution that becomes conductive due to condensation. These
are sheltered locations where neither temperature nor humidity is controlled. The area is protected from direct sunshine,
rain, or direct wind.
Polution Degree 4. Pollution that generates persistent conductivity through conductive dust, rain, or snow. Typical outdoor
locations.
Pollution Degree
Pollution Degree 2 (as defined in IEC 61010-1). Note: Rated for indoor use only.
xiv 20 A Current Probes Instruction Manual
Environmental Considerations
This section provides information about the environmental impact of the product.
Product End-of-Life Handling
Observe the following guidelines when recycling an instrument or component:
Compliance Information
Equipment recycling.
contain substances that could be harmful to the environment or human health if improperly handled at the product’s end of life. To
avoid release of such substances into the environment and to reduce the use of natural resources, we encourage you to recycle this
product in an appropriate system that will ensure that most of the materials are reused or recycled appropriately.
This symbol indicates that this product complies with the applicable European Union requirements according to
Directives 2002/96/EC and 2006/66/EC on waste electrical and electronic equipment (WEEE) and batteries.
For information about recycling options, check the Support/Service section of the Tektronix Web site
(www.tektronix.com).
Production of this equipment required the extraction and use of natural resources. The equipment may
Restriction of Hazardous Substances
This product is classified as Monitoring and Control equipment, and is outside the scope of the 2002/95/EC RoHS Directive.
20 A Current Probes Instruction Manual xv
Compliance Information
xvi 20 A Current Probes Instruction Manual
Preface
This manual describes the installation and operation of the TCP0020 & TCP2020 current probes. Basic probe operations and
concepts are presented in this manual. You can also access the Tektronix Web site for this document and other related information.
Documentation
Preface
To read about Use these documents
TCP0020 & TCP2020 Probes: First Time Operation, Functional
Check, Operating Basics, Specifications, Performance
Verification
In-depth oscilloscope operation, user interface help, GPIB
commands
*
To access the documentation that is installed on your instrument, click
Read this Instruction Manual.
Access the online help from the Help menu on the host
instrument.
in the taskbar and select
Start
*
Programs > TekApplications
.
Conventions Used in This Manual
The following icon is used throughout this manual to indicate a step sequence.
20 A Current Probes Instruction Manual xvii
Preface
Returning the Probe for Servicing
If your probe requires servicing, you must return the probe to Tektronix. If the original packaging is unfit for use or not available, use
the following packaging guidelines:
Preparation for Shipment
Use a corrugated cardboard shipping
1.
carton having inside dimensions at
least one inch greater than the probe
dimensions. The box should have a carton
test strength of at least 200 pounds.
Put the probe into an antistatic bag or wrap
2.
it to protect it from dampness.
Place the probe into the box and stabilize it
3.
with light packing material.
Seal the carton with shipping tape.
4.
Refer to
5.
beginning of this manual for the shipping
address.
xviii 20 A Current Probes Instruction Manual
Contacting Tektronix
at the
Key Features
Use the TCP0020 & TCP2020 current probes to make accurate measurements from DC to 50 MHz. The probes combine proven
Hall-effect technology with the Tektronix TekVPI oscilloscope interface. Key features include:
TCP0020 Current Probe
AC coupling (on TekVPI oscilloscopes that
support AC coupling)
10 mA sensitivity (on TekVPI oscilloscopes
that support the 1 mV/div setting)
100 A peak pulse current
(pulse widths <10 μs)
Direct scaling and unit readout on host
instruments
Probe control through the TekVPI
oscilloscope menus or remotely through
the oscilloscope
150V CAT II (Bare wire), 300V CAT II
(Insulated wire)
Key Features
20 A Current Probes Instruction Manual 1
Key Features
TCP2020 Current Probe
>50 MHz bandwidth, <7 ns rise time
AC/DC measurement capability
20 A RMS continuous rating
(de-rated with frequency)
100 A peak pulse current
(pulse widths <10 μs)
1% DC accuracy (typical)
One-button degauss
150V CAT II (Bare wire), 300V CAT II
(Insulated wire)
External power supply allows use on any
1MΩ-input measuring instrument
2 20 A Current Probes Instruction Manual
Installation
TCP0020 Probe
SlidetheTCP0020probeintothe
1.
oscilloscope input. The probe snaps in
when fully engaged.
All of the probe LEDs light brieflyfora
quick visual check, and then the
LED flashes red to indicate a degauss is
required.
The
degauss is run, when the probe senses and
adjusts per the host attenuation setting.
Degauss the probe. (See page 5,
2.
Degaussing the Probes
To disconnect the probe, press the latch
3.
button and pull the probe away from the
instrument.
50 Ω Te rm
Installation
Degauss
LED glows green until the
.)
20 A Current Probes Instruction Manual 3
Installation
TCP2020 Probe
Align the BNC connector on the probe to
1.
the oscilloscope input connector.
Push in the probe connector and turn it to
2.
the right to lock it in place.
Connect the AC adapter to a line source
3.
and then connect it to the probe.
The AC adapter can also be connected
NOTE.
to the probe before connecting the probe to the
oscilloscope.
When the probe is connected to the
oscilloscope and the AC adapter, the probe
LED lights green.
Power
Degauss the probe. (See page 5,
4.
Degaussing the Probes
To disconnect the probe, turn the probe
connector to the left and pull the probe away
from the instrument.
.)
4 20 A Current Probes Instruction Manual
Degaussing the Probes
After the TCP0020 probe is connected
1.
to the oscilloscope, the multicolor
Degauss/AutoZero
red to indicate a degauss is required.
The oscilloscope screen display may also
prompt you to degauss the probe.
The TCP2020 probe does not indicate
that a degauss is needed, but you should
always degauss a current probe after
connecting it to the oscilloscope.
To degauss the probe, firstverifythatthe
2.
Jaw Open
probe slider forward to lock the jaw closed.
LED is not lit. If it is lit, push the
status LED flashes
Installation
20 A Current Probes Instruction Manual 5
Installation
Press the
3.
DegaussorDegauss/AutoZero
button on the probe or in the Degauss
window on the host instrument.
As degauss runs, the
50 Ω Ter m
LED may go
on or off as the termination is set for proper
current measurements.
The DC gain and offset errors
NOTE.
are not guaranteed when the multicolor
Degauss/AutoZero status LED flashes red.
The multicolor
4.
Degauss/AutoZero
status
LED on the TCP0020 probe glows green
to indicate a successful degauss routine
was run, and that the probe is in normal
operating mode.
6 20 A Current Probes Instruction Manual
Quick Tip
To maintain measurement accuracy, degauss
your probe in each of these cases:
After you turn on the measurement system
and allow a 20-minute warm-up period
Before you connect the probe to a
conductor
Whenever a current or thermal overload
condition occurs
Whenever you subject the probe to a
strong external magnetic field
Installation
20 A Current Probes Instruction Manual 7
Controls and Indicators
Controls and Indicators
The TCP0020 and TCP2020 probes share the same probe head design and some common features. Controls and indicators that
are unique to each probe model are covered in the separate sections that follow.
Probe Head
Slider and Conductor Jaw
When the slider is in the locked position,
1.
you can degauss the probe and take
measurements.
Move the slider to the unlocked position to
2.
insert and remove conductors to and from
the jaw.
Thejawcanaccepta5mm(0.2in)
3.
diameter maximum conductor size.
WARNING.
force conductors larger than 5 mm (0.2 in)
diameter into the jaw.
To prevent probe damage, do not
8 20 A Current Probes Instruction Manual
Safe handling zone – keep fingers behind
4.
demarcations when taking measurements.
WARNING.
To avoid electrical shock, do not
access the area beyond the safe handling zone
(indicated by the shaded area) when you take
measurements.
Controls and Indicators
WARNING.
To prevent probe damage, do not
drop the probe or subject it to impact.
WARNING.
Do not connect the current probe
to any wire that carries voltages or currents that
exceed the rating of the probes.
20 A Current Probes Instruction Manual 9
Controls and Indicators
TCP0020 Probe
This section describes the controls and indicators for the TCP0020 probe. The following section covers the TCP2020 probe. (See
page 20,
Power On Indication
When the TCP0020 probe is powered on, all
of the indicator LEDs light briefly, and then the
Degauss/AutoZero
red to indicate that a degauss is required.
After you degauss the probe, the
Degauss/AutoZero
indicate a successful degauss. This LED also
functions as a power on indicator.
TCP2020 Probe
.)
LED on the probe flashes
LED glows green to
10 20 A Current Probes Instruction Manual
Jaw Open LED
Controls and Indicators
The
1.
Jaw Open
slider is unlocked.
Push the probe slider forward to lock it
2.
andtoturnofftheLED.Inthelocked
position, you can degauss the probe, or
when connected to a conductor, accurately
measure current.
CAUTION.
than 5.0 mm (0.20 in) diameter. Damage to the
probe jaw may result.
LED glows when the probe
Do not measure conductors larger
20 A Current Probes Instruction Manual 11
Controls and Indicators
Overload LED
The
Overload
specifications are being exceeded. When the
LED glows red, the maximum input continuous
current limit has been exceeded.
CAUTION.
conditions that cause the Overload LED to light
for extended periods.
LED alerts you that the probe
Do not subject the probe to
Quick Tip
An input current overload can magnetize
the probe. Always degauss the probe after
an overload.
12 20 A Current Probes Instruction Manual
Degauss/AutoZero Button
Controls and Indicators
The
Degauss/AutoZero
and nulls any DC offset in the probe.
To degauss the probe, do the following:
Disconnect the probe from any conductors,
1.
and then close and lock the slider.
Press the
2.
initiate the degauss routine.
After successfully completing the Degauss
routine, the
the probe glows green.
Degauss/AutoZero
Degauss/AutoZero
button degausses
button to
LED on
20 A Current Probes Instruction Manual 13
Controls and Indicators
Degauss/AutoZero LED
When the multicolor
LED flashes red, you must degauss the probe.
The Degauss/AutoZero function also nulls any
DC offset in the probe.
If the LED flashes orange, you should degauss
the probe. The DC gain and offset errors are
not guaranteed when this LED flashes orange.
The LED glows green after successfully
completing the Degauss/AutoZero routine.
Degauss/AutoZero
status
14 20 A Current Probes Instruction Manual
50 Ω Term LED
This LED lights when the output signal path
in the probe is actively terminated to 50 Ω.
For the LED to correctly indicate the probe
termination, you must degauss the probe after
you connect it to the oscilloscope, or if you
change the oscilloscope termination while the
probe is connected to the oscilloscope.
When you connect the probe to a 1M Ω
input host, the
you degauss the probe. When the probe is
connectedtoa50Ω input host, the
LED turns off after you degauss the probe.
NOTE.
an oscilloscope input termination of 50 Ω,the
maximum peak current that you can measure
is 50 amps, with a pulse duration of no more
than 20 us.
50 Ω Te rm
When you are using the probe with
LED lights after
50 Ω Te rm
Controls and Indicators
20 A Current Probes Instruction Manual 15
Controls and Indicators
Menu Button
Press the
to access additional probe functions, such as
probe offset and deskew.
The following menus may appear on the
oscilloscope screen, depending on the model.
An MSO/DPO4000 series oscilloscope is used
in this example.
Press the
1.
The lower-bezel menu appears at
the bottom of the screen, above the
lower-bezel buttons.
Press the
2.
lower-bezel menu.
As each lower-bezel menu item is
3.
highlighted, a side-bezel menu appears
for that function, next to the right-bezel
buttons. The Probe Setup menu is shown.
Press the probe
4.
close the menu.
button on the TCP0020 probe
Menu
button on the probe.
Menu
button to scroll through the
More
button again to
Menu
16 20 A Current Probes Instruction Manual
Controls and Indicators
Menu-Driven Probe Functions
The following probe functions are available through menu screens on many Tektronix oscilloscopes. An MSO/DPO4000 series
oscilloscope is used in these examples.
Fine Scale.
the vertical mA/div setting to a custom scale
that is between the fixed 1–2–5 scales on many
oscilloscopes.
For example, to display a 320 mA signal over
exactly 8 vertical divisions (40 mA/div), first set
the fixed scale to 50 mA/div. Next, select Fine
Scale from the lower-bezel menu and then use
the Multipurpose knob to adjust the Fine Scale
down to 40 mA/div, as displayed on-screen.
Offset and Position.
selections allow you to adjust that parameter
andtoreturnthevaluetozerobypressinga
side-bezel button.
20 A Current Probes Instruction Manual 17
Thisfeatureallowsyoutoadjust
Each of these
Controls and Indicators
Probe Setup.
displays the current range and attenuation
(20 amperes and 10X for the TCP0020 and
TCP2020 probes).
Side-bezel buttons allow you to run the
Degauss and AutoZero routines. The buttons
also display the degauss status of the probe.
The Probe Setup menu
18 20 A Current Probes Instruction Manual
Controls and Indicators
Deskew.
TCP2020 probes to other probes, select
this function and connect the probes to the
optional deskew fixture. (See page 30,
Deskew/Calibration Fixture
The deskew procedure measures the
channel-to-channel delay time, including the
probes, and provides manual and automatic
steps to align the delay (skew). Refer to
your oscilloscope manual or deskew fixture
documentation for instructions.
To deskew the TCP0020 and
.)
20 A Current Probes Instruction Manual 19
Controls and Indicators
TCP2020 Probe
This section describes the controls and indicators for the TCP2020 probe.
Power LED
The TCP2020 probe is powered by an external
DC power supply that is included with the
probe.
The probe will pass through AC signals
NOTE.
without the external power supply connected,
but the performance is not guaranteed.
When the external DC power supply is
connected to the TCP2020 probe, the
LED glows green.
Power
20 20 A Current Probes Instruction Manual
Degauss Button
The Degauss button degausses and nulls any
DC offset in the probe.
To degauss the probe, do the following:
Disconnect the probe from the current
1.
source.
Close and lock the slider.
2.
Controls and Indicators
Press the
3.
degauss routine.
A decaying oscillation appears on the
oscilloscope as the degauss operation
completes.
20 A Current Probes Instruction Manual 21
Degauss
button to initiate the
Controls and Indicators
Jaw Open LED
When the
1.
slider is unlocked.
Push the probe slider forward to lock it
2.
and to turn off the LED. In the locked
position, you can degauss the probe, or
when connected to a conductor, accurately
measure current.
CAUTION.
than 5.0 mm (0.20 in) diameter. Damage to the
probe jaw may result.
Jaw Open
Do not measure conductors larger
LED glows, the probe
22 20 A Current Probes Instruction Manual
Balance Control
Use the Balance control (thumb wheel) to make
minor adjustments to DC offsets present on the
probe output. To use the control:
Disconnect the probe from the current
1.
source.
Lock the probe slider closed.
2.
Controls and Indicators
Press the
3.
Set the oscilloscope vertical scale to
4.
10 mA/div, or the most-sensitive setting on
the instrument.
Open and close the probe slider.
5.
Adjust the
6.
displayed signal.
NOTE.
opening below the thumb wheel (see small arrow, above). First, set the thumb wheel to the midway point, and then use an
insulated, straight-edge tool on the coarse balance adjustment to set the offset to zero.
20 A Current Probes Instruction Manual 23
Degauss
Balance
If you cannot set the DC offset to zero with the thumb wheel, a coarse balance adjustment is accessible through the
button.
control to zero the
Functional Check
Functional Check
The following procedure checks that your probe is functioning properly. To verify that your probe meets the warranted specifications,
refer to the
Performance Verification
procedures. (See page 61.)
CAUTION.
conductors larger than 5.0 mm diameter into the probe jaw. Damage to the probe may result.
To check that your probe functions correctly,
do the following:
1.
2.
3.
4.
5.
24 20 A Current Probes Instruction Manual
The probe jaw opening accommodates insulated conductors with a diameter of 5.0 mm or less. Do not insert
Connect the probe to any channel of the
oscilloscope.
Set the oscilloscope to display the probe
channel.
Degauss the probe.
Clamp the probe to your circuit.
Adjust the oscilloscope or use the Autoset
function to display a stable waveform.
When you see a stable waveform, your
probe is functioning correctly.
Accessories and Options
This section lists the standard and optional accessories available for the probe, and provides information on how to use the
accessories. Specifications are provided where appropriate so that you can choose the accessory that best fits your needs.
Accessories and Options
20 A Current Probes Instruction Manual 25
Accessories and Options
Standard Accessories
Probe Ground Lead
Fasten the small clip to the ground stub on
1.
the probe body.
Clip the alligator clip to your circuit ground.
2.
Attach the probe to your circuit.
3.
Reorder Tektronix part number:
196-3521-xx, qty. 1
26 20 A Current Probes Instruction Manual
NylonCarryingCasewithPouch
and Inserts
Use the carrying case to hold the probe, the
accessories, and the instruction manual.
Place the probe, accessories, and manual
1.
in the carrying case.
Close the carrying case to transport the
2.
accessories to another location or for
storage.
Reorder Tektronix part number:
016-1952-xx
DC Power Supply (TCP2020 Only)
The TCP2020 probe requires an external DC
power supply for proper operation.
Reorder Tektronix part number:
119-7836-xx
Accessories and Options
20 A Current Probes Instruction Manual 27
Accessories and Options
Instruction Manual
The instruction manual provides operating and
maintenance instructions.
Reorder Tektronix part number:
071-3002-xx
Manuals in the languages listed below are
available for this product. Other languages may
also be available; check the Tektronix Web site
at www.tektronix.com/manuals.
(Japanese)
(Simplified Chinese)
28 20 A Current Probes Instruction Manual
Optional Accessories
This section lists the optional accessories that you can purchase to help you with your probing tasks.
Current Loop
This 1-turn, 50 Ω current loop is required for
the performance verification procedures. The
BNC connector allows for easy connections to
current sources, and the conductor bar inside
the fixture fits in the jaw of the current probe.
To use the current loop, follow the procedure
for the specific task that you are performing
(for example, Performance Verification or
Adjustments).
Order Tektronix part number:
067-2396-xx
Accessories and Options
20 A Current Probes Instruction Manual 29
Accessories and Options
Deskew/Calibration Fixture
Connect this fixture to host instruments that
support the probe calibration or deskew
procedures. The deskew procedures
compensate for gain errors and timing
differences between current and voltage
probes. Refer to your oscilloscope manual or
fixture documentation for instructions.
Order Tektronix part number: 067-1686-xx
30 20 A Current Probes Instruction Manual
Options
Service Options
Accessories and Options
Option C3.
Option C5.
Option D1.
Option D3.
Option D5.
Option R3.
Option R5.
20 A Current Probes Instruction Manual 31
Calibration Service 3 years
Calibration Service 5 years
Calibration Data Report
Calibration Data Report, 3 years (with Option C3)
Calibration Data Report, 5 years (with Option C5)
Repair Service 3 years
Repair Service 5 years
Basic Operation
Basic Operation
CAUTION.
surfaces of the probe head transformer are precision-polished and should be handled with care. Measurements may be degraded
by dirt on the mating surfaces of the probe head transformer. Refer to the Maintenance section of this manual for information on
how to properly clean the probe head transformer surfaces.
1.
2.
3.
Do not force conductors larger than 5.0 mm (0.20 in) into the probe jaws. Damage to the probe may result. The mating
Check the oscilloscope display before
connecting the probe to a conductor.
If there is a DC offset, degauss the probe.
(See page 5,
youareusingtheTCP2020probe,youmay
also need to adjust the Balance control.
(See page 23,
Close and lock the probe jaw over the
conductor.
For correct polarity reading, connect the
probe so that the current flow, from positive
to negative, is aligned with the arrow on
the probe jaw.
Read the measurement on the oscilloscope
display.
Degaussing the Probes
Balance Control
.)
.) If
32 20 A Current Probes Instruction Manual
Grounding the Probe
Use the ground lead to improve EMI rejection at high frequencies.
Clip the ground lead to the ground post at
1.
the bottom of the probe head.
Connect the alligator end of the clip to the
2.
circuit ground.
Basic Operation
20 A Current Probes Instruction Manual 33
Probing Principles
Probing Principles
The following information is provided to help you use the full potential of your current probe.
Degaussing a Probe with an Unpowered Conductor in the Jaws
You can degauss your current probe while a conductor of an unpowered circuit is clamped in the jaws. The advantage of
degaussing with an unpowered circuit is that any offset from stray DC magnetic fields is compensated. Degaussing with the
conductor in the probe jaws eliminates the need to manually remove the probe.
Be certain that the conductor in the probe jaws is completely unpowered. Any current flowing through the conductor will
NOTE.
cause a residual offset in the current probe and may cause an inaccurate measurement or an error condition.
The impedance of your circuit should be higher than 10 mΩ for the degauss procedure to work. (The probe core might not saturate
with a circuit impedance of less than 10 mΩ). While degauss occurs, the probe will induce a signal of about 50 mV into 50 Ω,at
about 170 Hz in the unpowered circuit. Your circuit must be able to absorb this induced voltage. With low impedance circuits,
several amperes may be induced in the circuit being measured. This may be of concern when you are using very small conductors.
34 20 A Current Probes Instruction Manual
Measuring Differential Current
To simplify your differential or null current
measurements, you can place two conductors
in one current probe.
Probing Principles
WARNING.
probe. An uninsulated conductor is any conductor without insulation or without insulation rated for the voltage present on the
conductor under test. If the circuit voltage is above 150 V CAT II, but less than 300 V CAT II, you can take the measurement, but
only on an insulated conductor. Do not exceed the 300 V CAT II voltage rating on any insulated conductor.
An insulated conductor is any conductor that is surrounded by an insulating material that is capable of isolating the voltage present
on the conductor. Lacquer coatings like those typically found on transformer windings do not provide sufficient, reliable insulation
for use with current probes. The lacquer coating can be easily nicked or damaged, compromising the insulating capabilities of
the lacquer coating.
Do not force the slide closed. Damage to the probe may result. If you cannot close the slide around the conductor(s), either reduce
the number of conductors you are measuring, or, if possible, take your measurement on a smaller conductor.
20 A Current Probes Instruction Manual 35
When you are taking measurements on uninsulated conductors, do not exceed the 150 V CAT II voltage limit of the
Probing Principles
Orient the two conductors under test so
1.
that the polarities (+ and –) oppose each
other.
Clamp the current probe around the two
2.
conductors. Be careful not to pinch a
conductor in the probe jaws.
Measure the current.
3.
Conventional current flows from positive to
negative. A waveform above the baseline
indicates that the conductor with the
conventional current flow in the direction
of the probe arrow is carrying the greater
current.
36 20 A Current Probes Instruction Manual
To adjust for a current null, adjust the
4.
current in one of the conductors until
the DC component of the displayed
measurement is zero.
Extending Current Range
If your measurement exceeds the maximum current rating of the connected probe, you can extend the AC and DC current ranges
without exceeding specified limits by using the following methods.
Probing Principles
WARNING.
applicable accessories. When using multiple conductors, do not exceed current limits on either conductor.
To avoid personal injury or equipment damage, do not exceed the specified electrical limits of the probe or any
Extending DC Range
If you want to measure a low-amplitude AC component that is superimposed on an extremely large steady-state DC component
(such as in a power supply), or if you want to extend the DC current range of your probe, you can add offset (bucking) current with
a second conductor.
20 A Current Probes Instruction Manual 37
Probing Principles
WARNING.
Do not put more than one uninsulated conductor at a time in the probe jaws. An uninsulated conductor is any
conductor without insulation or without insulation rated for the voltage present on the conductor under test.
To supply additional bucking current:
Place a second conductor that has a pure
1.
DC component of known value in the probe
jaw with the conductor under test.
Orient the second conductor so that the
2.
bucking current flows in the opposite
direction of the DC flow in the conductor
under test.
To determine measurement values, add
3.
the value of the bucking current to the
displayed measurement.
Adding a second conductor to the probe increases the insertion impedance and reduces the upper bandwidth limit of the
NOTE.
probe. Winding multiple turns further increases the insertion impedance, further reducing the upper bandwidth limit.
38 20 A Current Probes Instruction Manual
To increase the value of the bucking current:
Wind multiple turns of the second
1.
conductor around the probe.
The bucking current is equal to the current
flowing in the conductor, multiplied by the
number of turns wound around the probe.
For example, if the second conductor has a
current of 100 mA DC and is wrapped around
the probe five times, the DC bucking current is
100 mA multiplied by 5, or 500 mA DC.
Probing Principles
20 A Current Probes Instruction Manual 39
Probing Principles
Increasing Sensitivity
If you are measuring DC or low-frequency
AC signals of very small amplitudes, you can
increase measurement sensitivity of your
Current Probe by doing the following:
Wind several turns of the conductor under
1.
test around the probe as shown. The
signal is multiplied by the number of turns
around the probe.
To obtain the actual current value, divide
2.
the displayed amplitude by the number of
turns.
For example, if a conductor is wrapped around
the probe three times and the oscilloscope
shows a reading of 3 mA DC, the actual current
flow is 3 mA divided by 3, or 1 mA DC.
Winding more turns around the probe increases the insertion impedance and reduces the upper bandwidth limit of the probe.
NOTE.
40 20 A Current Probes Instruction Manual
Common Mode Noise/Magnetic Field Errors
Common-mode noise at high frequencies and
strong magnetic fields on the supply side of
your circuit can cause measurement errors. To
avoid this:
Measure on the low or ground side of your
1.
circuit.
Orient the probe to measure conventional
2.
current flow (from positive to negative).
This method works best when the
NOTE.
negative terminal shown in the diagram is tied
to earth ground.
Probing Principles
20 A Current Probes Instruction Manual 41
Probing Principles
AC and DC Coupling
You can couple the signal input to the oscilloscope with either DC or AC coupling. DC coupling shows both the DC and AC
measurement components. AC coupling removes the DC component from the displayed signal. Use your oscilloscope controls to
change the coupling.
This low-frequency square wave is
1.
displayed using AC coupling. The signal
exhibits low-frequency rolloff.
Press the DC Coupling button to display
2.
the waveform as truly square.
CAUTION.
sure that the input DC current does not exceed
the probe specifications.
When you use AC coupling, make
42 20 A Current Probes Instruction Manual
Maximum Current Limits
Current probes have three maximum current ratings: pulsed, continuous, and Ampere-second product. Exceeding any of these
ratings can saturate the probe core, which magnetizes the core and causes measurement errors. Refer to the specifications for the
maximum current ratings of the probe. (See Table 2 on page 54.)
Probing Principles
Maximum Pulsed Current (I
maxP
)isthe
maximum peak value of pulsed current the
probe can accurately measure, regardless
of how short (within bandwidth limitations)
the pulse duration is.
Maximum Continuous Current (I
maxC
)isthe
maximum current that can be continuously
measured at DC or at a specified AC
frequency. The maximum continuous
current value is derated with frequency;
as the frequency increases, the maximum
continuous current rating decreases.
20 A Current Probes Instruction Manual 43
Probing Principles
Ampere-Second Product is the maximum
width of pulsed current that you can
measure when the pulse amplitude is
between the maximum continuous and
maximum pulsed current specifications.
The maximum continuous specification
varies by frequency.
To determine if your measurement exceeds
the Ampere-second product, you must first
determine the maximum allowable pulse width
or maximum allowable pulse amplitude, as
described in the following section.
NOTE.
current, or Ampere-second product rating of the probe. Exceeding these ratings can magnetize the probe and cause measurement
errors.
Always degauss the probe after measuring a current that exceeds the maximum continuous current, maximum pulsed
44 20 A Current Probes Instruction Manual
Maximum Allowable Pulse Width
To determine the maximum allowable pulse
width do the following:
Measure the peak current of the pulse.
1.
Divide the Ampere-second (or
2.
Ampere-microsecond) specification
for the probe by the measured peak current
of the pulse:
The quotient is the maximum allowable
pulse width (PW
Check that the pulse width at the 50% point
3.
of the measured signal is less than the
calculated maximum allowable pulse width
).
(PW
max
max
).
Probing Principles
20 A Current Probes Instruction Manual 45
Probing Principles
Maximum Allowable Pulse Amplitude
To determine the maximum allowable pulse
amplitude do the following:
Measure the pulse width at the 50% points.
1.
Divide the Ampere-second (or
2.
Ampere-microsecond) specification
for the range setting of the probe by the
pulse width.
The quotient is the maximum allowable
pulse amplitude; the peak amplitude of the
measured pulse must be less than this
value.
For example, the TCP0020 and TCP2020
probes have a maximum Ampere-second
product of 1000 A-μs. If a pulse measured with
the probe has a width of 11 μs, the maximum
allowable peak current would be 1000 A-μs
divided by 11 μs, or 90.9 A.
46 20 A Current Probes Instruction Manual
Application Examples
This section explains ways to use your probe in common troubleshooting tasks and how to extend the use of your measurement
system.
Application Examples
20 A Current Probes Instruction Manual 47
Application Examples
Inductance Measurements
You can use the current probe to measure the inductance of coils that have either a low-impedance or high-impedance pulse
source of a known value.
Low-Impedance Pulse Sources
This figure shows a constant-voltage pulse
generator of extremely low output impedance
connected to an inductor that has low
resistance.
Connect the inductor across the output
1.
terminals of the pulse generator.
Maintain a constant voltage across the
2.
inductor.
Clamp the current probe over one of the
3.
source leads.
If the probe impedance is a significant
NOTE.
part of the total circuit inductance, measurement
accuracy will be affected. Refer to the probe
specifications for probe insertion impedance.
48 20 A Current Probes Instruction Manual
Measure the current ramp. The inductance
4.
is effectively defined by the slope of the
current ramp shown here.
Calculate the inductance using the
5.
following formula:
where:
L
is the inductance in henries,
E
is the voltage of the pulse generator,
dt
is the change in time, and
di
is the change in current.
Application Examples
20 A Current Probes Instruction Manual 49
Application Examples
High-Impedance Pulse Sources
If the pulse source has a higher impedance of
known resistance, such that the output voltage
drops as the current increases, the inductance
of a coil can be calculated by the time constant
of the charge curve.
The current ramp shows how the values for the
inductance formula are obtained.
Use this formula to calculate the inductance
based on the current measurement:
where:
L
is the inductance in henries,
τ
is the time required for the current to rise
or fall 63.2% of the total current value, and
R
is the source resistance of the pulse
generator.
50 20 A Current Probes Instruction Manual
Measuring Inductor Turns Count
To obtain an approximate turns count of an
inductor, do the following:
Connect the inductor to a current limited
1.
source, as shown.
Measure the input current on one of the
2.
inductor leads.
Clamp the current probe around the
3.
inductor and note the current value.
The number of turns is equal to the ratio of coil
current to input current.
The accuracy of this method is limited by the
current measurement accuracy.
Application Examples
20 A Current Probes Instruction Manual 51
Application Examples
For a more precise turns count, you need a
coil with a known number of turns to use as a
reference. Do the following:
Repeat steps 1 and 2 above and make the
1.
following changes:
Insert the reference coil into the current
2.
probe.
Insert the test coil into the current probe
3.
so that the currents oppose each other
as shown. You must observe the polarity
of coil current to determine whether the
test coil has less or more turns than the
reference coil. The turns are calculated by
using the formula:
where:
is the number of turns in the test coil,
N
2
is the number of turns in the reference
N
1
coil,
is the measured coil current, and
I
m
is the input current.
I
1
52 20 A Current Probes Instruction Manual
Specifications
The specifications in Tables 1 through 5 are valid under the following conditions:
The probe has been calibrated at an ambient temperature of 23 °C ±5 °C.
The probe is connected to a host instrument with an input impedance of 1 M Ω. The TCP0020 probe specifications are also
valid on host instruments with an input impedance of 50 Ω.
The probe must have a warm-up period of at least 20 minutes and be in an environment that does not exceed the limits
described. (See Table 1).
The probe has been degaussed successfully.
Specifications for the TCP0020 & TCP2020 current probes fall into three categories: warranted, typical, and nominal characteristics.
Warranted Characteristics
Warranted characteristics describe guaranteed performance within tolerance limits or certain type-tested requirements. Warranted
characteristics that have checks in the
Table 1: Warranted electrical characteristics
Characteristic Description
DC gain accuracy
Rise time (10% to 90%)
Bandwidth
Performance Verification
section are marked with the
<3%
≤7ns
DC to 50 MHz
Specifications
symbol.
20 A Current Probes Instruction Manual 53
Specifications
Typical Characteristics
Typical characteristics describe typical but not guaranteed performance.
Table 2: Typical electrical characteristics
Characteristic Description
Maximum continuous current – DC and low frequency 20 A RMS
Maximum peak current
TCP0020 with 50 Ω oscilloscope termination 50 A maximum peak pulse (pulse width ≤20 μs)
TCP0020 & TCP2020 with 1 MΩ oscilloscope termination 100 A maximum peak pulse (pulse width ≤10 μs)
Displayed RMS noise ≤1.0 mA RMS (limit measurement bandwidth to 20 MHz)
Insertion impedance
Signal delay
Maximum voltage on bare wire
Maximum voltage on insulated wire
Maximum Amp·Second product 1000 A·μs (See page 43,
(See Figure 3 on page 57.)
(See Figure 2 on page 56.)
~14.5 ns
150 V CAT II
300 V CAT II
Maximum Current Limits
.)
54 20 A Current Probes Instruction Manual
Figure 1: Frequency derating (continuous peak current versus frequency)
Specifications
20 A Current Probes Instruction Manual 55
Specifications
Figure 2: Typical insertion impedance versus frequency
56 20 A Current Probes Instruction Manual
Figure 3: Maximum peak pulse versus pulse width
Specifications
20 A Current Probes Instruction Manual 57
Specifications
Table 3: Environmental characteristics
Characteristic Description
Temperature
Humidity
Altitude
Table 4: Typical mechanical characteristics
Characteristic TCP0020 TCP2020
Compensation box
(See Figure 4 on page 59.)
Probe head
Jaw opening (maximum measurable conductor size) 5 mm (0.20 in)
Cable length (from probe head to compensation box) 2 m (79 in)
Unit weight
Probe only
Probe, accessories, and packaging
Operating: 0 to +50 °C (+32 to +122 °F)
Nonoperating: -40 to +75 °C (-40 to +167 °F)
Operating: 5-95% RH, tested up to +30 °C (+86 °F)
5-85% RH, tested at +30 °C to +50 °C (+86 °F to +122 °F)
Nonoperating: 5-95% RH, tested up to +30 °C (+86 °F)
5-85% RH, tested at +30 °C to +75 °C (+86 °F to +167 °F)
Operating: Up to 3000 meters (10,000 feet),
Nonoperating: Up to 12,192 meters (40,000 feet)
77 mm × 30.5 mm × 40.6 mm
(4.2 in × 1.6 in × 1.0 in)
148.3 mm × 15.2 mm × 30.5 mm (5.8 in × 0.6 in × 1.2 in)
226.8 g (8 oz)
1219g(2lb11oz)
73.1 mm × 30.5 mm × 40.6 mm
(4.2 in × 1.0 in × 1.6 in)
226.8 g (8 oz)
1219g(2lb11oz)
58 20 A Current Probes Instruction Manual
Figure 4: Mechanical dimensions
Specifications
20 A Current Probes Instruction Manual 59
Specifications
Nominal Characteristics
Nominal characteristics describe guaranteed traits, but the traits do not have tolerance limits.
Table 5: Nominal electrical characteristics
Characteristic Description
Input coupling
Current range
Power requirement
TCP0020
TCP2020
Termination
TCP0020
TCP2020
Oscilloscope compatibility
TCP0020
TCP2020
DC
20 A
Supplied by host instrument
External; 12 VDC @ 300 mA (100–240 VAC, 50–60 Hz, 0.5 A input)
Terminate output into 50 Ω or 1 MΩ
Terminate output into 1 MΩ
Tektronix oscilloscopes equipped with the TekVPI interface
Oscilloscopes with a 1 MΩ BNC input
60 20 A Current Probes Instruction Manual
Performance Verification
The procedures that follow verify the warranted specifications of the probe, listed below. The recommended calibration interval is
one year.
DC gain accuracy
Rise time
Bandwidth
Perform the following verification procedures in the order listed.
Performance Verification
20 A Current Probes Instruction Manual 61
Performance Verification
Equipment Required
Table 6 lists the equipment required for the performance verification procedure.
Table 6: Test equipment
Description and quantity Performance requirement Recommended example
Oscilloscope TekVPI interface, 500 MHz or greater bandwidth Tektronix DPO4000
High Amplitude Pulse
Generator
Calibrator DCV: 0.2% accuracy, 0 to ±1.5 V, square wave output
TekVPI Calibration/Verification
2
adapter
Digital multimeter (DMM) ≥2 volt range, ≥1% accuracy
DC current loop 5 turns 18 AWG coated wire on 3 inch form See instructions that follow
HF current loop
Adapter
2
Adapter
BNC cable 50 Ω, 0.76 m (30 in) length
1
Nine-digit part numbers (xxx-xxxx-xx) are Tektronix part numbers
2
Required for TCP0020 probe only
Risetime <500 ps, pulse width ≥100 ns, amplitude
>10 Vpp into 50 Ω
ACA: 0.25% accuracy, 0 to ±6 A, square wave output
TekV P I i n t erfa c e
50 Ω ±0.5%, BNC male connector
BNC-to-dual banana
SMA male-to-BNC female
1
Picosecond Labs 2600C
Fluke 9100
067-1701-xx
Keithley 2700
067-2396-xx
103-0090-xx
015-1018-xx
012-0117-xx
62 20 A Current Probes Instruction Manual
Making the DC Current Loop
Construct the loop using #18 coated wire and a cylindrical form approximately 3 inches in diameter:
exactly
Wind
1.
around the form.
Scrape about a half-inch of coating off of
2.
the ends of the wire.
5 turns of #18 coated wire
Performance Verification
Ensure that the current loop has exactly 5 turns. A significant error will result for each turn variance from 5 turns.
NOTE.
20 A Current Probes Instruction Manual 63
Performance Verification
Equipment Setup
Use the following procedure to set up and warm up the equipment to test the probes.
Turn on the oscilloscope.
1.
Connect the probe to any channel of the
2.
oscilloscope. If you are testing a TCP2020
probe, connect the external DC power
supply to the probe.
Degauss the probe.
3.
Set the oscilloscope coupling to DC.
4.
Power on the remaining test equipment.
5.
Allow 20 minutes for the equipment to
6.
warm up.
Photocopy the test record and use it to
7.
record the test results. (See page 71.)
64 20 A Current Probes Instruction Manual
DC Gain Accuracy
This test checks the DC gain accuracy of the probe. If the measurements are out of the specified limits in the test record, refer to
Adjustments
the
TCP2020 Setup
Connect a BNC-to-Dual Banana adapter to
1.
the digital multimeter (DMM) input.
Connect the TCP2020 probe output to the
2.
BNC adapter attached to the DMM.
section. (See page 72.)
Performance Verification
Proceed to step 6 in the
3.
TCP2020 Test
TCP0020 & TCP2020 Test
20 A Current Probes Instruction Manual 65
section. (See page 67,
TCP0020 &
.)
Performance Verification
TCP0020 Setup
Connect a BNC-to-Dual Banana adapter to
1.
the digital multimeter (DMM) input.
Connect the SMA M-to-BNC F adapter
2.
to the SMA output of the TekVPI
Calibration/Verification adapter.
Connect the BNC cable between
3.
the BNC adapter on the TekVPI
Calibration/Verification adapter and the
BNC adapter attached to the DMM.
Connect the TekVPI Calibration/Verification
4.
adapter to any channel (1–4) of the
oscilloscope.
Connect the probe to the TekVPI
5.
Calibration/Verification adapter.
The adapter is only used to supply
NOTE.
power to the probe; measurements are taken
on the DMM.
66 20 A Current Probes Instruction Manual
TCP0020 & TCP2020 Test
Do not clamp the current probe around any
6.
conductor, but make sure the jaw is in the
locked position.
Degauss the probe by pressing the
7.
DegaussorDegauss/AutoZero
Connect the 5-turn current loop to the
8.
current source, and then clamp the current
probe around the 5-turn current loop as
shown. The arrow indicator on the probe
should point away from the (+) terminal of
the current source.
Set the current source output to +2.00 A.
9.
Set the DMM to measure DC volts, on
10.
≥2 volt range (or use Autoset).
Enable the output of the current source.
11.
Performance Verification
button.
20 A Current Probes Instruction Manual 67
Performance Verification
Record the exact measurement of the
12.
DMM as M1.
Set the current source output to -2.00 A.
13.
Record the exact measurement of the
14.
DMM as M2.
Compute the % Error using the measured
15.
amplitude values and the formula shown.
For example, you might measure values of
0.975 V for M1 and –0.995 V for M2. With
an expected output voltage (Ve) of 1.000 V,
compute the % Error as shown.
Disable the calibrator output.
16.
If the computed % Error is out of the specified
limit, the probe may require an adjustment.
(See page 72,
Adjustments
.)
Test current = ±10.00 A (±2.00 A source output x 5 coil turns)
Expected output voltage (Ve) = 1.00 V (1 mV/10 mA)
Example:
68 20 A Current Probes Instruction Manual
Rise Time and Bandwidth
This procedure verifies that the probes meet the rise time specification by directly measuring the rise time. The bandwidth of the
probe is then calculated using the measured probe rise time.
Connect a BNC cable to the output of the
1.
pulse generator.
Connect the other end of the BNC cable to
2.
the HF current loop.
Set the pulse generator output and pulse
3.
width to maximum. (50 Vp-p, positive
pulse, 100 ns duration, repetitive output.)
Set the oscilloscope to display the entire
4.
waveform on-screen:
Vertical sensitivity to 200 mA/div
Horizontal to 20 ns/div
Trigger at 20%
Averaging on (32)
Coupling to DC
Performance Verification
Automeasurement to Rise Time
20 A Current Probes Instruction Manual 69
Performance Verification
Connect the probe to any channel (1–4)
5.
Degauss the probe.
6.
Clamp the current probe around the HF
7.
current loop. Verify that the arrow indicator
on the probe points away from the pulse
generator.
The rise time is displayed on the
8.
oscilloscope. Record the rise time
measurement in the Test Record.
Calculate the probe bandwidth using the
9.
measured rise time in the following formula:
Record the calculated bandwidth value in
10.
the test record.
Disable the generator output.
11.
End of procedures.
70 20 A Current Probes Instruction Manual
Test Record
Performance Verification
Probe Model/Serial Number:
Temperature:
Date of Calibration:
Performance test
DC gain accuracy
Rise time ~1 A <7.0 ns NA 7.0 ns
Bandwidth NA >50 MHz 50 MHz NA
Test current Expected output Minimum Incoming
±10.0 A 1.000 V
Certificate Number:
RH %:
Technician:
Outgoing
-3% +3%
Maximum
20 A Current Probes Instruction Manual 71
Adjustments
Adjustments
The procedures that follow describe adjustments to the probe to bring the performance within the warranted specifications.
DC gain accuracy
Prerequisites
Complete the
Keep the test setup intact for the adjustment procedure.
CAUTION.
handling the probe.
72 20 A Current Probes Instruction Manual
DC Gain Accuracy Test
To avoid ESD damage to the probe, use an antistatic wrist strap and work at a static-approved workstation when
Performance Verification
in the
procedure. (See page 65,
DC Gain Accuracy
.)
DC Gain Accuracy
Adjustments
This procedure describes the DC gain accuracy adjustments for the probe. You must complete the
Performance Verification
Set the calibrator output to 2.0 A.
1.
Set the digital multimeter (DMM) to measure DC
2.
volts, ≥2.0 V range.
Measure the output amplitude on the DMM.
3.
Access the DC gain control through the opening in
4.
the probe head as shown. Adjust the DC gain control
to display 1.000 V, ±10 mV on the DMM.
Disconnect the probe from the calibrator and disable
5.
the output.
procedure before making this adjustment. Leave the test setup intact to perform the adjustment.
DC Gain Accuracy Test
in the
20 A Current Probes Instruction Manual 73
Maintenance
Maintenance
This section contains maintenance information for your probe.
Troubleshooting
The TCP2020 current probe is designed to work with all oscilloscopes that have BNC inputs. The TCP0020 current probe can only
be used with Tektronix oscilloscopes that have TekVPI inputs. The LEDs on the TCP0020 probe normally indicate the operational
status, but they also alert you to error conditions affecting the probe. If the probe LEDs do not light as expected, or if some of the
probe features do not work properly, an error condition may exist. See the following table.
Table 7: Probe troubleshooting
Symptom
LEDs on the probe flash or remain on:
Jaw Open
This LED is common to
NOTE.
both probes. The 3 remaining LED
status descriptions only apply to the
TCP0020 probe.
Overload
74 20 A Current Probes Instruction Manual
Possible cause
Continuous red: The conductor jaw is unlocked. Move the slider forward to lock
the jaw closed.
Flashing: An intermittent, repetitive overload is present on the probe. Remove the
probe from the current source. (See page 37,
Continuous red: The measured current exceeds the limit of the probes. Remove
the probe from the current source. (See page 37,
Extending Current Range
Extending Current Range
.)
.)
Table 7: Probe troubleshooting (cont.)
Maintenance
Symptom
Degauss/AutoZero
50 Ω Term Off: The probe is connected to an instrument that is terminated with a 50 ohm input.
LEDs on the probe do not light. The oscilloscope channel may be bad: Try another channel or another oscilloscope.
An error message displays on the
oscilloscope.
Possible cause
Flashing red: The probe requires degaussing. Degauss the probe.
Flashing amber: The probe is performing the degauss routine.
Continuous green: The probe is degaussed and ready for use.
Continuous green: The probe is connected to an instrument that is terminated
with a 1 M ohm input.
The probe is automatically set to the correct termination when the degauss routine
is run.
All LEDs should light briefly and then the Degauss/AutoZero LED should flash.
If the probe functions correctly on another channel or oscilloscope, the contacts on
the input channel that exhibits the problem may need to be cleaned. Refer to your
oscilloscope manual for the proper cleaning procedure.
If the probe does not work on another channel or oscilloscope, the probe is
defective, and must be returned to Tektronix for repair.
The message will describe the cause and solution. For example, if the
degauss needed
message appears, perform the degauss procedure.
Probe
20 A Current Probes Instruction Manual 75
Maintenance
Cleaning
Protect the probe from adverse weather conditions. The probe is not waterproof.
CAUTION.
the probe during exterior cleaning.
Do not use chemical cleaning agents; they may damage the probe. Avoid using chemicals that contain benzine, benzene,
toluene, xylene, acetone, or similar solvents.
Clean the exterior surfaces of the probe with a dry, lint-free cloth or a soft-bristle brush. If dirt remains, use a soft cloth or swab
dampened with a 75% isopropyl alcohol solution and rinse with deionized water. A swab is useful for cleaning narrow spaces on the
probe, use only enough solution to dampen the swab or cloth. Do not use abrasive compounds on any part of the probe.
76 20 A Current Probes Instruction Manual
To prevent damage to the probe, do not expose it to sprays, liquids, or solvents. Avoid getting moisture inside
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