Tektronix Keithley 2651A User manual

Reference Manual
2651A-901-01 Rev. C October 2021
*P2651A-901-01C*
2651A-901-01C
tek.com/keithley
Model 2651A High Power
System SourceMeter Instrument

High Power System SourceMeter®Instrument
Reference Manual
Model 2651A

© 2021, Keithley Instruments, LLC
Cleveland, Ohio, U.S.A.
All rights reserved.
Any unauthorized reproduction, photocopy, or use of the information herein, in whole or in part,
without the prior written approval of Keithley Instruments, LLC, is strictly prohibited.
These are the original instructions in English.
TSPTM, TSP-LinkTM, and TSP-NetTM are trademarks of Keithley Instruments, LLC. All Keithley
Instruments product names are trademarks or registered trademarks of Keithley Instruments, LLC.
Other brand names are trademarks or registered trademarks of their respective holders.
The Lua 5.0 software and associated documentation files are copyright © 1994 - 2015, Lua.org,
PUC-Rio. You can access terms of license for the Lua software and associated documentation at
the Lua licensing site (https://www.lua.org/license.html).
Microsoft, Visual C++, Excel, and Windows are either registered trademarks or trademarks of
Microsoft Corporation in the United States and/or other countries.
Document number: 2651A-901-01 Rev. C October 2021

Safety precautions
The following safety precautions should be observed before using this product and any associated instrumentation. Although
some instruments and accessories would normally be used with nonhazardous voltages, there are situations where hazardous
conditions may be present.
This product is intended for use by personnel who recognize shock hazards and are familiar with the safety precautions required
to avoid possible injury. Read and follow all installation, operation, and maintenance information carefully before using the
product. Refer to the user documentation for complete product specifications.
If the product is used in a manner not specified, the protection provided by the product warranty may be impaired.
The types of product users are:
Responsible body is the individual or group responsible for the use and maintenance of equipment, for ensuring that the
equipment is operated within its specifications and operating limits, and for ensuring that operators are adequately trained.
Operators use the product for its intended function. They must be trained in electrical safety procedures and proper use of the
instrument. They must be protected from electric shock and contact with hazardous live circuits.
Maintenance personnel perform routine procedures on the product to keep it operating properly, for example, setting the line
voltage or replacing consumable materials. Maintenance procedures are described in the user documentation. The procedures
explicitly state if the operator may perform them. Otherwise, they should be performed only by service personnel.
Service personnel are trained to work on live circuits, perform safe installations, and repair products. Only properly trained
service personnel may perform installation and service procedures.
Keithley products are designed for use with electrical signals that are measurement, control, and data I/O connections, with low
transient overvoltages, and must not be directly connected to mains voltage or to voltage sources with high transient
overvoltages. Measurement Category II (as referenced in IEC 60664) connections require protection for high transient
overvoltages often associated with local AC mains connections. Certain Keithley measuring instruments may be connected to
mains. These instruments will be marked as category II or higher.
Unless explicitly allowed in the specifications, operating manual, and instrument labels, do not connect any instrument to mains.
Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector jacks or test
fixtures. The American National Standards Institute (ANSI) states that a shock hazard exists when voltage levels greater than
30 V RMS, 42.4 V peak, or 60 VDC are present. A good safety practice is to expect that hazardous voltage is present in any
unknown circuit before measuring.
Operators of this product must be protected from electric shock at all times. The responsible body must ensure that operators
are prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential
human contact. Product operators in these circumstances must be trained to protect themselves from the risk of electric shock. If
the circuit is capable of operating at or above 1000 V, no conductive part of the circuit may be exposed.
Do not connect switching cards directly to unlimited power circuits. They are intended to be used with impedance-limited
sources. NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective
devices to limit fault current and voltage to the card.
Before operating an instrument, ensure that the line cord is connected to a properly-grounded power receptacle. Inspect the
connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.
When installing equipment where access to the main power cord is restricted, such as rack mounting, a separate main input
power disconnect device must be provided in close proximity to the equipment and within easy reach of the operator.
For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to the circuit under
test. ALWAYS remove power from the entire test system and discharge any capacitors before: connecting or disconnecting
cables or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth)
ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the
voltage being measured.

For safety, instruments and accessories must be used in accordance with the operating instructions. If the instruments or
accessories are used in a manner not specified in the operating instructions, the protection provided by the equipment may be
impaired.
Do not exceed the maximum signal levels of the instruments and accessories. Maximum signal levels are defined in the
specifications and operating information and shown on the instrument panels, test fixture panels, and switching cards.
When fuses are used in a product, replace with the same type and rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as protective earth (safety ground)
connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use
of a lid interlock.
If a screw is present, connect it to protective earth (safety ground) using the wire recommended in the user documentation.
The symbol on an instrument means caution, risk of hazard. The user must refer to the operating instructions located in the
user documentation in all cases where the symbol is marked on the instrument.
The symbol on an instrument means warning, risk of electric shock. Use standard safety precautions to avoid personal
contact with these voltages.
The symbol on an instrument shows that the surface may be hot. Avoid personal contact to prevent burns.
The symbol indicates a connection terminal to the equipment frame.
If this symbol is on a product, it indicates that mercury is present in the display lamp. Please note that the lamp must be
properly disposed of according to federal, state, and local laws.
The WARNING heading in the user documentation explains hazards that might result in personal injury or death. Always read
the associated information very carefully before performing the indicated procedure.
The CAUTION heading in the user documentation explains hazards that could damage the instrument. Such damage may
invalidate the warranty.
The CAUTION heading with the symbol in the user documentation explains hazards that could result in moderate or minor
injury or damage the instrument. Always read the associated information very carefully before performing the indicated
procedure. Damage to the instrument may invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits —including the power
transformer, test leads, and input jacks —must be purchased from Keithley. Standard fuses with applicable national safety
approvals may be used if the rating and type are the same. The detachable mains power cord provided with the instrument may
only be replaced with a similarly rated power cord. Other components that are not safety-related may be purchased from other
suppliers as long as they are equivalent to the original component (note that selected parts should be purchased only through
Keithley to maintain accuracy and functionality of the product). If you are unsure about the applicability of a replacement
component, call a Keithley office for information.
Unless otherwise noted in product-specific literature, Keithley instruments are designed to operate indoors only, in the following
environment: Altitude at or below 2,000 m (6,562 ft); temperature 0 °C to 50 °C (32 °F to 122 °F); and pollution degree 1 or 2.
To clean an instrument, use a cloth dampened with deionized water or mild, water-based cleaner. Clean the exterior of the
instrument only. Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that
consist of a circuit board with no case or chassis (e.g., a data acquisition board for installation into a computer) should never
require cleaning if handled according to instructions. If the board becomes contaminated and operation is affected, the board
should be returned to the factory for proper cleaning/servicing.
Safety precaution revision as of June 2017.

Introduction..............................................................................................................1-1
Welcome .............................................................................................................................. 1-1
Extended warranty ............................................................................................................... 1-1
Contact information.............................................................................................................. 1-1
Customer documentation..................................................................................................... 1-2
Organization of manual sections...............................................................................................1-2
Capabilities and features...................................................................................................... 1-3
Model-specific capabilities ................................................................................................... 1-4
General information.............................................................................................................. 1-4
Displaying the serial number.....................................................................................................1-4
General operation ....................................................................................................2-1
General ratings..................................................................................................................... 2-1
Controls, indicators, and connectors.................................................................................... 2-2
Front panel................................................................................................................................2-2
Rear panel.................................................................................................................................2-6
Cooling vents ....................................................................................................................... 2-8
Starting up your instrument.................................................................................................. 2-9
Procedure..................................................................................................................................2-9
Placing the Model 2651A in standby.......................................................................................2-10
Warmup period........................................................................................................................2-10
Line frequency configuration...................................................................................................2-10
Fuse replacement ...................................................................................................................2-11
System information ............................................................................................................ 2-11
Menu overview................................................................................................................... 2-11
Menu navigation......................................................................................................................2-11
Menu trees..............................................................................................................................2-13
Setting values.......................................................................................................................... 2-16
Beeper................................................................................................................................ 2-18
Display mode ..................................................................................................................... 2-19
Basic operation .................................................................................................................. 2-19
Operation overview.................................................................................................................2-19
Operation considerations for the ADC.....................................................................................2-25
Basic source-measure procedure ...........................................................................................2-27
Triggering in local mode..........................................................................................................2-30
Configuring trigger attributes in local mode.............................................................................2-31
Configuring for measure-only tests using the MODE key........................................................2-32
Voltmeter and ammeter measurements..................................................................................2-33
Ohms measurements.............................................................................................................. 2-34
Power measurements.............................................................................................................2-37
Contact check measurements.................................................................................................2-40
Saved setups ..........................................................................................................................2-42
DUT test connections......................................................................................................... 2-45
Input/output connectors...........................................................................................................2-45
2-wire local sensing connections.............................................................................................2-47
Table of contents

Table of contents Model 2651A High Power System SourceMeter® Instrument Reference Manual
4-wire remote sensing connections.........................................................................................2-48
Contact check connections .....................................................................................................2-49
Multiple SMU connections.......................................................................................................2-50
Combining SMU outputs .........................................................................................................2-51
Guarding and shielding ...........................................................................................................2-57
Test fixture ..............................................................................................................................2-62
Floating a SMU .......................................................................................................................2-63
DUT connection settings.................................................................................................... 2-64
Sense mode selection.............................................................................................................2-64
Output-off states......................................................................................................................2-65
USB storage overview........................................................................................................ 2-69
Connecting the USB flash drive ..............................................................................................2-70
File system navigation.............................................................................................................2-70
Displayed error and status messages................................................................................ 2-71
Range................................................................................................................................. 2-71
Available ranges...................................................................................................................... 2-72
Maximum source values and readings.................................................................................... 2-72
Measure autodelay..................................................................................................................2-73
Ranging limitations..................................................................................................................2-73
Manual ranging .......................................................................................................................2-73
Autoranging.............................................................................................................................2-74
Low range limits......................................................................................................................2-74
Range considerations .............................................................................................................2-75
Range programming ...............................................................................................................2-76
Digits .................................................................................................................................. 2-77
Setting display resolution from the front panel ........................................................................2-77
Setting display resolution from a remote interface ..................................................................2-77
Speed................................................................................................................................. 2-78
Setting the speed from the front panel ....................................................................................2-78
Setting the speed using the remote interface..........................................................................2-79
Remote communications interfaces................................................................................... 2-80
Supported remote interfaces...................................................................................................2-80
Output queue ..........................................................................................................................2-81
LAN communications..............................................................................................................2-81
GPIB operation........................................................................................................................2-83
General bus commands..........................................................................................................2-86
Front-panel GPIB operation ....................................................................................................2-88
RS-232 interface operation .....................................................................................................2-90
Functions and features............................................................................................3-1
Relative offset ...................................................................................................................... 3-1
Enabling and disabling relative offset from the front panel........................................................3-1
Defining a relative offset value from the front panel..................................................................3-2
Relative offset commands.........................................................................................................3-2
Filters.................................................................................................................................... 3-3
Filter types.................................................................................................................................3-3
Response time..........................................................................................................................3-4
Enabling the filter from the front panel ......................................................................................3-4
Configuring the filter from the front panel..................................................................................3-5
Setting the filter using a remote interface..................................................................................3-5
Reading buffers.................................................................................................................... 3-6
Front-panel reading buffer control.............................................................................................3-6
Remote reading buffer programming ......................................................................................3-11

Model 2651A High Power System SourceMeter® Instrument Reference Manual Table of contents
Sweep operation ................................................................................................................ 3-21
Sweep characteristics.............................................................................................................3-23
Configuring and running sweeps.............................................................................................3-31
Sweeping using factory scripts................................................................................................3-33
Sweep programming examples...............................................................................................3-34
Triggering........................................................................................................................... 3-36
Remote triggering overview..................................................................................................... 3-36
Using the remote trigger model...............................................................................................3-38
SMU event detectors...............................................................................................................3-42
Using trigger events to start actions on trigger objects............................................................3-44
Digital I/O port and TSP-Link synchronization lines ................................................................3-45
Timers.....................................................................................................................................3-48
Event blenders........................................................................................................................3-57
LAN triggering overview..........................................................................................................3-58
Command interface triggering.................................................................................................3-60
Manual triggering ....................................................................................................................3-60
Interactive triggering................................................................................................................3-61
Hardware trigger modes..........................................................................................................3-65
Understanding synchronous triggering modes........................................................................3-69
High-capacitance mode ..................................................................................................... 3-73
Understanding high-capacitance mode...................................................................................3-73
Enabling high-capacitance mode............................................................................................ 3-76
Display operations.............................................................................................................. 3-79
Display functions and attributes ..............................................................................................3-79
Display features ......................................................................................................................3-79
Display messages...................................................................................................................3-81
Input prompting.......................................................................................................................3-85
Indicators.................................................................................................................................3-87
Local lockout........................................................................................................................... 3-88
Load test menu .......................................................................................................................3-88
Running a test from the front panel.........................................................................................3-90
Key-press codes .....................................................................................................................3-90
Digital I/O ........................................................................................................................... 3-92
Port configuration.................................................................................................................... 3-92
Digital I/O configuration........................................................................................................... 3-94
Controlling digital I/O lines.......................................................................................................3-94
Using output enable ................................................................................................................3-96
Interlock...................................................................................................................................3-98
TSP-Link trigger lines..............................................................................................................3-98
Theory of operation ................................................................................................. 4-1
Analog-to-digital converter................................................................................................... 4-1
Source-measure concepts................................................................................................... 4-2
Limit principles ..........................................................................................................................4-2
Overheating protection..............................................................................................................4-3
Operating boundaries................................................................................................................4-5
Basic circuit configurations......................................................................................................4-20
Guard......................................................................................................................................4-24
Cable considerations...............................................................................................................4-26
Measurement settling time considerations......................................................................... 4-27
Programming example for controlling settling time delay........................................................4-28
Effects of load on current source settling time................................................................... 4-28
Creating pulses with the Model 2651A SMU ..................................................................... 4-29

Table of contents Model 2651A High Power System SourceMeter® Instrument Reference Manual
Pulse rise and fall times..........................................................................................................4-29
Pulse width..............................................................................................................................4-30
Remote commands..................................................................................................5-1
Introduction to TSP operation .............................................................................................. 5-1
Controlling the instrument by sending individual command messages .....................................5-1
Queries .....................................................................................................................................5-3
Information on scripting and programming................................................................................5-3
About TSP commands......................................................................................................... 5-4
Beeper control...........................................................................................................................5-4
Bit manipulation and logic operations........................................................................................5-4
Data queue................................................................................................................................5-5
Digital I/O ..................................................................................................................................5-5
Display ......................................................................................................................................5-6
Error queue............................................................................................................................... 5-7
Event log...................................................................................................................................5-7
File I/O ......................................................................................................................................5-7
GPIB .........................................................................................................................................5-8
Instrument identification ............................................................................................................5-9
LAN and LXI..............................................................................................................................5-9
Miscellaneous .........................................................................................................................5-10
Parallel script execution ..........................................................................................................5-11
Queries and response messages............................................................................................ 5-11
Reading buffer.........................................................................................................................5-12
Reset.......................................................................................................................................5-12
RS-232....................................................................................................................................5-13
Saved setups ..........................................................................................................................5-13
Scripting..................................................................................................................................5-13
SMU........................................................................................................................................5-14
SMU calibration.......................................................................................................................5-15
Status model...........................................................................................................................5-16
Time........................................................................................................................................5-17
Triggering................................................................................................................................5-17
TSP-Link .................................................................................................................................5-19
TSP-Net ..................................................................................................................................5-20
Userstrings..............................................................................................................................5-20
Factory scripts.................................................................................................................... 5-21
Running a factory script ..........................................................................................................5-21
Retrieving and modifying a factory script listing ......................................................................5-22
KISweep factory script ............................................................................................................5-22
KIPulse factory script ..............................................................................................................5-23
KIHighC factory script .............................................................................................................5-24
KIParlib factory script ..............................................................................................................5-25
KISavebuffer factory script......................................................................................................5-25
Instrument programming......................................................................................... 6-1
Fundamentals of scripting for TSP....................................................................................... 6-1
What is a script?........................................................................................................................6-2
Runtime and nonvolatile memory storage of scripts..................................................................6-2
What can be included in scripts?...............................................................................................6-3
Commands that cannot be used in scripts................................................................................6-3
Manage scripts..........................................................................................................................6-3
Working with scripts in nonvolatile memory.............................................................................6-11
Programming example: Interactive script................................................................................6-13
Fundamentals of programming for TSP............................................................................. 6-15
What is Lua?........................................................................................................................... 6-15

Model 2651A High Power System SourceMeter® Instrument Reference Manual Table of contents
Lua basics...............................................................................................................................6-15
Standard libraries.................................................................................................................... 6-30
Script with a for loop................................................................................................................6-34
Test Script Builder.............................................................................................................. 6-34
Installing the TSB software......................................................................................................6-35
Using Test Script Builder (TSB) ..............................................................................................6-35
Project navigator.....................................................................................................................6-36
Script editor.............................................................................................................................6-37
Outline view.............................................................................................................................6-37
Programming interaction.........................................................................................................6-38
Working with TSB Embedded............................................................................................ 6-39
Send individual instrument commands with TSB Embedded..................................................6-40
Password management ..................................................................................................... 6-41
Setting the password from a command or web interface ........................................................ 6-42
Unlocking the remote interface................................................................................................6-43
Resetting the password...........................................................................................................6-43
Advanced scripting for TSP ............................................................................................... 6-44
Global variables and the script.user.scripts table....................................................................6-44
Create a script using the script.new() command .....................................................................6-45
Rename a script......................................................................................................................6-48
Retrieve a user script ..............................................................................................................6-50
Delete user scripts from the instrument...................................................................................6-52
Restore a script to the runtime environment ...........................................................................6-53
Memory considerations for the runtime environment ..............................................................6-53
TSP-Link system expansion interface................................................................................ 6-55
Master and subordinates......................................................................................................... 6-55
TSP-Link system.....................................................................................................................6-56
TSP-Link nodes.......................................................................................................................6-56
Connections............................................................................................................................6-57
Initialization .............................................................................................................................6-57
Resetting the TSP-Link network..............................................................................................6-58
Accessing nodes.....................................................................................................................6-59
Using the reset() command.....................................................................................................6-60
Using the abort command.......................................................................................................6-60
Triggering with TSP-Link......................................................................................................... 6-60
TSP advanced features...........................................................................................................6-61
Using groups to manage nodes on TSP-Link network............................................................6-64
Running simultaneous test scripts........................................................................................... 6-65
Using the data queue for real-time communication.................................................................6-67
Copying test scripts across the TSP-Link network..................................................................6-67
Removing stale values from the reading buffer cache ............................................................6-67
TSP-Net ............................................................................................................................. 6-68
TSP-Net capabilities................................................................................................................6-68
Using TSP-Net with any ethernet-enabled instrument ............................................................ 6-69
TSP-Net compared to TSP-Link to communicate with TSP-enabled devices.........................6-71
TSP-Net instrument commands: General device control ........................................................6-71
TSP-Net instrument commands: TSP-enabled device control ................................................6-71
Example: Using tspnet commands..........................................................................................6-72
TSP command reference.........................................................................................7-1
TSP command programming notes ..................................................................................... 7-1
Placeholder text ........................................................................................................................7-1
Syntax rules ..............................................................................................................................7-2
Time and date values................................................................................................................7-2
Remote versus local state......................................................................................................... 7-3