Tektronix Keithley 4225-PMU User manual

User's Manual
4200A-PMU-900-01 Rev. B March 2023
*P4200A-PMU-900-01B*
4200A-PMU-900-01B
tek.com/keithley
Model 4200A-SCS
Pulse Card (PGU and PMU)

Pulse Card (PGU and PMU)
User's Manual
Model 4200A-SCS

© 2023, Keithley Instruments
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 is strictly prohibited.
All Keithley Instruments product names are trademarks or registered trademarks of Keithley
Instruments, LLC. Other brand names are trademarks or registered trademarks of their
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Document number: 4200A-PMU-900-01 Rev. B March 2023

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 2018.

Introduction..............................................................................................................1-1
Models 4220-PGU and 4225-PMU ...................................................................................... 1-1
Connections .............................................................................................................2-1
Introduction .......................................................................................................................... 2-1
Connection guidelines.......................................................................................................... 2-1
PMU common connections .......................................................................................................2-2
Shield connections....................................................................................................................2-2
Cable length..............................................................................................................................2-3
High frequency connections......................................................................................................2-3
Prober chuck connections.........................................................................................................2-4
PGU and PMU connectors................................................................................................... 2-4
Model 4225-RPM ................................................................................................................. 2-5
RPM input, output, and top panels............................................................................................2-5
Connecting the RPM to the PMU..............................................................................................2-6
Mounting the RPM ....................................................................................................................2-8
RPM diagrams for local and remote sensing.............................................................................2-8
Using the RPM as a switch.......................................................................................................2-9
Two-terminal device connections....................................................................................... 2-10
Three-terminal device connections.................................................................................... 2-12
Four-terminal device connections...................................................................................... 2-13
Pulse source-measure connections................................................................................... 2-15
Pulse generator connections...................................................................................................2-15
Using an adapter cable to connect pulse card to DUT ...................................................... 2-16
Connections to prober or test fixture bulkhead connectors ............................................... 2-16
RPM connections to DUT................................................................................................... 2-17
Two-terminal test connections.................................................................................................2-17
Remote sensing using RPM connections to a prober ............................................................. 2-18
PMU connection compensation ......................................................................................... 2-20
Short compensation................................................................................................................2-20
Offset current compensation...................................................................................................2-21
Perform connection compensation..........................................................................................2-21
Enabling connection compensation.........................................................................................2-22
Load-line effect compensation (LLEC) for the PMU .......................................................... 2-24
Methods to compensate for load-line effect.............................................................................2-25
How LLEC adjusts pulse output to the target levels................................................................2-25
Coping with the load-line effect...............................................................................................2-27
LLEC maintains even voltage spacing....................................................................................2-27
Test considerations.................................................................................................................2-28
LPT functions used to configure LLEC....................................................................................2-29
Enable LLEC...........................................................................................................................2-29
Disable LLEC and set the output impedance..........................................................................2-30
Setting up PMUs and PGUs in Clarius....................................................................3-1
Introduction .......................................................................................................................... 3-1
Table of contents

Table of contents
Model 4200A-SCS Pulse Card (PGU and PMU)
User's Manual
Configure the PGU, PMU, and RPM using tests ................................................................. 3-1
Create a PMU project........................................................................................................... 3-2
Configure the tests............................................................................................................... 3-3
PMU operation modes ......................................................................................................... 3-5
PMU - all terminal parameters ............................................................................................. 3-6
Start (PMU Amplitude Sweep) ..................................................................................................3-6
Stop (PMU Amplitude Sweep)...................................................................................................3-6
Step (Pulse Amplitude Sweep)..................................................................................................3-7
Points........................................................................................................................................3-7
Base..........................................................................................................................................3-7
Amplitude..................................................................................................................................3-7
Dual Sweep (pulse)...................................................................................................................3-8
Force Range (PMU)..................................................................................................................3-8
Disable outputs at completion...................................................................................................3-8
Current Spot Mean High ...........................................................................................................3-9
Current Spot Mean Low............................................................................................................3-9
Measure Current Range (PMU) ................................................................................................3-9
Low Range..............................................................................................................................3-10
Current Sample Waveform......................................................................................................3-10
Voltage Spot Mean High .........................................................................................................3-11
Voltage Spot Mean Low..........................................................................................................3-11
Voltage Sample Waveform......................................................................................................3-11
Report Timestamps.................................................................................................................3-11
Report Status (PMU)...............................................................................................................3-12
PMU measurement status.......................................................................................................3-12
Compensation Short Connection ............................................................................................3-15
Load Line Effect Compensation..............................................................................................3-15
DUT Resistance (R DUT)........................................................................................................3-15
Max Voltage Estimator............................................................................................................3-15
Threshold Current................................................................................................................... 3-15
Threshold Voltage...................................................................................................................3-16
Threshold Power.....................................................................................................................3-16
PMU Test Settings ............................................................................................................. 3-16
Pulse Settings.........................................................................................................................3-16
Timing Parameters..................................................................................................................3-20
PMU Advanced Test Settings .................................................................................................3-22
PMU capacitive charging/discharging effects.................................................................... 3-35
PMU and RPM measure ranges are not source ranges.................................................... 3-37
4220-PGU and 4225-PMU output limitations..................................................................... 3-38
Configure the PGU, PMU, and RPM using tests ............................................................... 3-38
Step or sweep multiple device terminals in the same test................................................. 3-39
Basic troubleshooting procedure ....................................................................................... 3-41
Step 1. Verify prober connections from the PMU or RPM to the DUT.....................................3-41
Step 2. Verify the pulse shape................................................................................................3-42
Step 3. Is the pulse level correct for each channel?................................................................3-43
Step 4. Is the pulse I-V curve suspect?...................................................................................3-43
Pulse card concepts ................................................................................................4-1
Models 4220-PGU and 4225-PMU ...................................................................................... 4-1
PMU block diagram...................................................................................................................4-2
Pulse modes .............................................................................................................................4-3

Model 4200A
-SCS Pulse Card (PGU and PMU) User's Manual Table
of contents
Pulse measurement types (PMU) .............................................................................................4-3
Measure modes ........................................................................................................................4-4
4200A-SCS power supply limitations................................................................................... 4-5
Pulse source-measure concepts.......................................................................................... 4-8
Ultra-fast I-V tests .....................................................................................................................4-8
Sample rate.............................................................................................................................4-10
Segment Arb waveform...........................................................................................................4-11
Full arb waveform....................................................................................................................4-15
Pulse waveforms for nonvolatile memory testing.................................................................... 4-16
Waveform capture...................................................................................................................4-17
DUT resistance determines pulse voltage across DUT...........................................................4-17
Triggering................................................................................................................................4-22
Measurement types............................................................................................................ 4-25
Spot mean measurements......................................................................................................4-26
Spot mean discrete readings...................................................................................................4-26
Spot mean average readings..................................................................................................4-27
Waveform measurements.......................................................................................................4-27
Waveform discrete readings....................................................................................................4-28
Waveform average readings...................................................................................................4-29
Measurement timing................................................................................................................4-30
KPulse (for Keithley Pulse Cards)...........................................................................5-1
Keithley Pulse Application.................................................................................................... 5-1
Starting KPulse .........................................................................................................................5-1
KPulse setup and help..............................................................................................................5-2
Triggering............................................................................................................................. 5-3
Standard pulse waveforms .................................................................................................. 5-4
Segment Arb waveforms...................................................................................................... 5-6
Exporting Segment Arb waveform files.....................................................................................5-8
Custom file arb waveforms (full arb) .................................................................................... 5-9
Custom Arb file operation: Select and configure waveforms...................................................5-10
Custom Arb file operation: Copy waveforms into Sequencer..................................................5-11
Custom Arb file operation: Load waveform and turn on output...............................................5-12
Waveform types......................................................................................................................5-13
Use the RPM to switch the SMU, CVU, and PMU...................................................6-1
Introduction .......................................................................................................................... 6-1
Included accessories............................................................................................................ 6-2
Equipment required.............................................................................................................. 6-3
Update the RPM configuration in KCon............................................................................... 6-3
Device connections.............................................................................................................. 6-4
Connection schematic...............................................................................................................6-4
Connect the 4200A-SCS to the DUT.........................................................................................6-5
Set up the measurements in Clarius.................................................................................... 6-6
Create a new project.................................................................................................................6-6
Add a device .............................................................................................................................6-7
Search for and select existing tests in the Test Library.............................................................6-8
Configure the vfd test................................................................................................................6-9
Configure the cv-diode test.....................................................................................................6-11
Configure the pulse-diode test ................................................................................................6-13

Table of contents
Model 4200A-SCS Pulse Card (PGU and PMU)
User's Manual
Run the test.............................................................................................................................6-15
View and analyze the test results............................................................................................6-15
PMU for pulsed I-V measurements on a MOSFET .................................................7-1
Introduction .......................................................................................................................... 7-1
Equipment required.............................................................................................................. 7-2
Device connections.............................................................................................................. 7-2
Connection schematic...............................................................................................................7-3
Set up the measurements in Clarius.................................................................................... 7-4
Create a new project.................................................................................................................7-5
Search for and select an existing test .......................................................................................7-5
Configure the test......................................................................................................................7-6
Run the test and analyze the results.........................................................................................7-8
Testing flash memory..............................................................................................8-1
Testing flash memory........................................................................................................... 8-1
Flash connection guidelines................................................................................................. 8-2
Programming and erasing flash memory ..................................................................................8-3
Endurance testing................................................................................................................ 8-8
Connections for endurance testing - no switching matrix..........................................................8-9
Connections for endurance testing - switching matrix.............................................................8-11
Disturb testing .................................................................................................................... 8-12
Connections for disturb testing................................................................................................8-12
Using a switching matrix .................................................................................................... 8-14
Use KPulse to create and export Segment Arb waveforms............................................... 8-14
Enter Segment Arb values into UTM array parameters..................................................... 8-16
Direct connections to single DUT....................................................................................... 8-17
Direct connections to array DUT for disturb testing........................................................... 8-19

In this section:
Models 4220-PGU and 4225-PMU........................................... 1-1
Models 4220-PGU and 4225-PMU
The 4220-PGU High Voltage Pulse Generator Unit and 4225-PMU Ultra-Fast Pulse Measure Unit are
high-speed pulse-generator cards for the 4200A-SCS. The 4220-PGU provides pulse output only.
The 4225-PMU provides both pulse output and pulse measurement. The PGU and PMU have similar
pulse output characteristics.
The 4225-PMU can be paired with one or two 4225-RPM Remote Preamplifier/Switch Modules. The
RPM is a remote amplifier and automatic switch. When the RPM is used as a preamplifier for the
PMU, it provides additional low-current measurement ranges. When the RPM is used as a switch, it
switches between the PMU, SMUs, and CVUs.
LPT functions that pertain to the PGU and PMU are documented in “LPT commands for PGUs and
PMUs” in Model 4200A-SCS LPT Library Programming.
To do quick tests with minimal interaction with other 4200A-SCS test resources, you can use the
Keithley Pulse Application (KPulse). KPulse is a nonprogramming alternative that you can use to
configure and control the installed Keithley pulse cards. Refer to KPulse (on page 5-1) for additional
information.
The simplified circuits of the 4220-PGU and 4225-PMU pulse generators are shown in the
following figure.
Section 1
Introduction

Section
1: Introduction Model 4200A-SCS Pulse Card (PGU and PMU)
User's Manual
1-2 4200A-PMU-900-01 Rev. B March 2023
Figure 1: Simplified circuits of the PGU and PMU

In this section:
Introduction .............................................................................. 2-1
Connection guidelines.............................................................. 2-1
PGU and PMU connectors....................................................... 2-4
Model 4225-RPM..................................................................... 2-5
Two-terminal device connections........................................... 2-10
Three-terminal device connections ........................................ 2-12
Four-terminal device connections .......................................... 2-13
Pulse source-measure connections....................................... 2-15
Using an adapter cable to connect pulse card to DUT........... 2-16
Connections to prober or test fixture bulkhead connectors.... 2-16
RPM connections to DUT....................................................... 2-17
PMU connection compensation.............................................. 2-20
Load-line effect compensation (LLEC) for the PMU............... 2-24
Introduction
Proper connection methods are critical to perform stable and accurate measurements using the PMU,
with or without the RPM. The guidelines in this chapter help prevent pulse voltage overshoot and
oscillations.
You can use the Multi-measurement Prober Cable Kits (4210-MMPC) to connect the 4200A-SCS to
perform pulse I-V measurements. These kits help maximize signal fidelity by eliminating the
measurement errors that often result from cabling errors. The prober cable kits include:
•4210-MMPC-C Multi-Measurement (I-V, C-V, Pulse) Prober Cable Kit for Cascade Microtech
12000 prober series
•4210-MMPC-S Multi-Measurement (I-V, C-V, Pulse) Prober Cable Kit for SUSS MicroTec
PA200/300 prober series
•4210-MMPC-L Multi-Measurement (I-V, C-V, Pulse) Prober Cable Kit for Lucas Signatone
probers
•4210-MMPC-W Multi-Measurement (I-V, C-V, Pulse) Prober Cable Kit for Wentworth
Laboratories probers
Connection guidelines
The following guidelines describe PMU common connections, shield connections, cable length, high
frequency connections, and prober chuck connections for the PMUs and PGUs.
Section 2
Connections

Section
2: Connections Model 4200A-SCS Pulse Card (PGU and PMU)
User's Manual
2-2 4200A-PMU-900-01 Rev. B March 2023
PMU common connections
Common LO for the PMU is the outer shells of the two SMA connectors. With an SMA cable
connected (see following figure), common LO is the outside shield of the cable.
Figure 2: PMU common low terminals
Because pulsing requires high frequency signal propagation, reduce cable inductance by minimizing
the loop area of the connection to the device under test (DUT).
Do not use the GNDU as common low for the PMU toavoid creating a large loop area. When using
the GNDU, an inductive loop area is created when the HI and LO leads are separated. Fast rise times
(dt), high current (di), and large inductances (L) can cause voltage overshoots, oscillations, and
ringing in the high-speed measurement circuit. This isbased on Lenz’s law: V= L di/dt.
Shield connections
For multiple PMU channels, you should connect the shields (common LO) from all PMU channels as
close as possible to the DUT. You reduce inductance by minimizing the loop area of the shield
connections. The figure in Using an adapter cable to connect pulse card to DUT (on page 2-16) and
the Local sensing (on page 2-17) figures illustrate proper shield connection schemes using the
supplied cabling.

Model 4200A
-SCS Pulse Card (PGU and PMU) User's Manual Section 2:
Connections
4200A-PMU-900-01 Rev. B March 2023 2-3
Cable length
Use the shortest possible cable length to achieve the highest frequency output, the best pulse shape,
and the best results. Here are reasons to avoid using longer cable lengths:
•Longer cable lengths have longer reflection times, which can slow down transmission times.
•Longer cables may have impedance mismatches, which can cause distortions.
•Higher capacitance in longer cables causes higher capacitive charging effects during the pulse
transitions (see PMU capacitive charging/discharging effects (on page 3-35)).
Only use the white SMA coaxial cables that are supplied with the PMU and RPM. These are 50 Ω
cables that match the internal 50 Ω resistance of the PMU. The PMU is supplied with 6.5 ft (2 m) SMA
cables and the RPM is supplied with 8 in. (20 cm) SMA cables. Always use the 8 in. (20 cm) SMA
cables with the RPM.
High frequency connections
Use these connection guidelines for high-speed testing (pulse width <1 μs).
•Use cables and connectors optimized for high frequency (at least 150 MHz). The SMA coaxial
cables supplied with the PMU and RPM are rated for high frequency.
•Probe manipulators must be rated at least 150 MHz.
•Properly connect the shields of the coaxial cables and minimize the loop area of the shield
connections (see Shield connections (on page 2-2)).
•Minimize cable length (see Cable length (on page 2-3)).
•Use a signal path that matches the impedance of the instrument (50 Ω). The SMA cables
supplied with the PMU and RPM are 50 Ω.

Section
2: Connections Model 4200A-SCS Pulse Card (PGU and PMU)
User's Manual
2-4 4200A-PMU-900-01 Rev. B March 2023
Prober chuck connections
When possible, avoid pulse connections to the prober chuck. If unavoidable, use these guidelines
when connecting to the prober chuck:
•When making connections to the back side of the wafer, PMU functionality will be diminished.
Use caution and verify waveforms.
•Generally, the chuck adds capacitance and noise. This reduces both low-current and high-speed
sampling performance.
•If one of the device terminals is the back side of the wafer, then pulse only on that terminal (on
chuck) and measure at another terminal using the second channel. If possible, do not measure
from the PMU channel connected to the chuck.
•For a two-terminal device, refer to Two-terminal device connections (on page 2-10), using figure
"Two-terminal device connections to a PMU using both channels" as a guide.
•For a four-terminal device, use the Four-terminal device connections (on page 2-13) to two PMUs
figure, or the Local sensing (on page 2-17) four-terminal figure as a guide (as applicable). This
cabling approach permits the low-side measurement approach described in PMU capacitive
charging/discharging effects (on page 3-35).
PGU and PMU connectors
The connectors for the PGU and PMU pulse cards are shown in the following figure.
Figure 3: 4220-PGU and 4225-PMU connectors

Model 4200A
-SCS Pulse Card (PGU and PMU) User's Manual Section 2:
Connections
4200A-PMU-900-01 Rev. B March 2023 2-5
Model 4225-RPM
The 4225-RPM is a remote amplifier/switch that is used as a current preamplifier for the 4225-PMU.
The RPM provides additional high-speed, low-current measurement ranges.
The RPM can also be used as a switch for the 4200-SMU, 4201-SMU, 4210-CVU, and 4215-CVU.
See Using the RPM as a switch (on page 2-9).
RPM input, output, and top panels
The input, output, and top panels for the RPM are shown in the following figure.
Figure 4: 4225-RPM panels
The RPM connector on the input panel connects to one of the RPM connectors (channel 1 or channel
2) on the 4225-PMU. The RPM also has input connectors for a 4200-SMU or 4201-SMU
(source-measure unit) and a 4210-CVU or 4215-CVU (capacitance-voltage unit).
The previous figure shows modes for the RPM LED colors. During normal Clarius operation, only the
red, green, or blue lights are shown. However, other colors or color combinations are possible. For
example, during the 4225-PMU self-test, the RPM LED alternates between purple and green for the
majority of the test, but there is a portion of the test where the LED flashes red and green. During
firmware upgrade of the 4225-PMU, the RPM LED is green, but flashes red and green near the end
of the process. During firmware upgrade of the 4225-RPM, the RPM LED is blue at the start, and
changes to green for the remainder of the process.
The output status of the 4200A-SCS is indicated by the Operate light on the front of the
4200A-SCS chassis.

Section
2: Connections Model 4200A-SCS Pulse Card (PGU and PMU)
User's Manual
2-6 4200A-PMU-900-01 Rev. B March 2023
RPM wiring diagram
The internal wiring diagram of the RPM is shown in the following figure.
Signals from the 4200A-SCS instrument cards are routed through the RPM to the output Force and
Sense connectors. Switching is used to control which card is connected to the output. See Using the
RPM as a switch (on page 2-9) for more information on switching.
The LEDs on the top panel (see the previous figure) indicate which card is connected to the output.
By default, the RPM (pulse mode) is connected to the output unless a SMU or CVU is switched in.
Figure 5: Wiring diagram of the RPM
Connecting the RPM to the PMU
Turn off the system and disconnect the power cord before connecting or disconnecting the
RPM to or from the PMU. Failure to do so may result in RPM or PMU damage, possibly
voiding the warranty.

Model 4200A
-SCS Pulse Card (PGU and PMU) User's Manual Section 2:
Connections
4200A-PMU-900-01 Rev. B March 2023 2-7
The RPM is matched to a PMU card and channel. Make sure to connect the RPM only to that PMU
card and channel. Labels on top of the RPM indicate the specific connection channel and PMU. For
example, "PMU1-2" indicates PMU1, channel 2.
With system power off, use the supplied RPM cable to connect a 4225-RPM to the matching RPM
channel of the 4225-PMU, as shown in the following figure.
Figure 6: 4225-PMU connection to an RPM
With an RPM installed, never make connections directly to any of the SMA connectors (CH1
and CH2) on the PMU. This may result in damage to the PMU or DUT. It may also produce
corrupt data.
After connecting or removing an RPM, always perform the procedure “Update the RPM
configuration” in Model 4200A-SCS Setup and Maintenance to ensure that KCon accurately
represents the present 4200A-SCS hardware configuration.

Section
2: Connections Model 4200A-SCS Pulse Card (PGU and PMU)
User's Manual
2-8 4200A-PMU-900-01 Rev. B March 2023
Mounting the RPM
When mounting the 4225-RPM, make sure that there is a minimum of 5 cm (2 in.) of space
between multiple RPM base assemblies. Spacing multiple 4225-RPM or 4200-PA instruments
closer than 5 cm (2 in.) from the 4200-MAG-BASE can cause the internal relays
to malfunction.
RPM diagrams for local and remote sensing
The following figure shows the diagram for local sensing. The center conductor of the Force triaxial
connector is connected to the high side of the device under test (DUT) while the outer shield is
connected to DUT LO. The Sense connector is not used.
Figure 7: RPM wiring diagram for local sensing
The following figure shows the diagram for remote sensing. Both Sense and Force are connected to
DUT HI.
Figure 8: Diagram for remote sensing

Model 4200A
-SCS Pulse Card (PGU and PMU) User's Manual Section 2:
Connections
4200A-PMU-900-01 Rev. B March 2023 2-9
Using the RPM as a switch
You can use the RPM to switch a PMU, CVU, or SMU to a DUT terminal. The RPM wiring diagram
(on page 2-6) figure shows the switches. The following figure shows a typical test configuration for
using an RPM as a switch for a PMU, SMU, and CVU. In general, one RPM per device terminal is
recommended. By default, the PMU (with RPM) is connected to the output unless a SMU or CVU is
switched in.
Figure 9: Test configuration for using RPM as a switch
Both the red cables (supplied with the CVU) and the blue cables (supplied with the optional
4210-MMPC cable kits) are 100 Ω. You can do remote sensing (on page 2-18) using the optional
4210-MMPC cable kits with the RPMs.
Control RPM switching
Before using an RPM, configure the 4200A-SCS by doing the steps in “Update the RPM
configuration” in Model 4200A-SCS Setup and Maintenance. This properly associates the instruments
connected to each RPM.
There are two methods to control RPM switching:
•ITM operation using automatic switching (after doing the steps in “Update the RPM
configuration”)
•UTM testing from within the user module, use the LPT function rpm_config
You must update the RPM configuration in KCon before using the RPM to control switching.
If you do not, corrupt test data may result due to incorrect switch settings in the RPM.