Keysight Technologies InfiniiMax III Series User manual

Keysight InfiniiMax III
Series Probes
User’s Guide

Notices
© Keysight Technologies, Inc. 2000 - 2014
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Manual Part Number
N2800-97010
Edition
April 2014
KeysightTechnologies, Inc.
1400 Fountaingrove Parkway
Santa Rosa, CA 95403 USA
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Safety Notices
CAUTION. CAUTION denotes a
hazard. It calls attention to a proce-
dure that, if not correctly performed
or adhered to, could result in dam-
age to or destruction of the product.
Do not proceed beyond a caution
note until the indicated conditions
are fully understood and met.
WARNING. WARNING denotes a
hazard. It calls attention to a proce-
dure which, if not correctly per-
formed or adhered to, could result
in personal injury or loss of life. Do
not proceed beyond a warning note
until the indicated conditions are
fully understood and met.

3
Contents
1 Using InfiniiMax III Series Probes
InfiniiMax III Probe Amplifiers 6
Proper Handling Techniques 9
InfiniiMax III and III+ Probing System Family Diagram 14
N5477A Sampling Scope Adapter 16
Cautions 17
SPICE Models for N5440A, N5447A, N5441A, N5445A, and N5444A Probe Heads 18
SPICE Models for N2838A and N2836A Probe Heads 24
Simplified InfiniiMax III Schematic 27
2 InfiniiMax III Probe Heads
N5445A InfiniiMax III Differential Browser Probe Head 30
N2848A InfiniiMax III+ QuickTip InfiniiMode Probe Head 35
N5439A InfiniiMax III ZIF (Zero Insertion Force) Probe Head 38
N2836A InfiniiMax III Solder-in Probe Head 47
N5441A InfiniiMax III Solder-in Probe Head 54
N5444A InfiniiMax III 2.92 mm / 3.5 mm / SMA Probe Head 62
3 Performance Specifications / Characteristics
4 Calibration / Deskew Procedure
Procedure 70
5 Performance Verification
Bandwidth Performance Verification 78
DC Input Resistance Performance Verification 95
Performance Test Record 99
6 Performance Plots
N2836A 26 GHz Solder-In Head (with N2803A) 103
N2838A/N5439A 25 GHz PCB ZIF Tip/Head (with N2803A) 106
N5440A/N5439A 28 GHz Ceramic ZIF Tip/Head (with N2803A) 109
N5447A/N5439A 28 GHz Ceramic High-Sensitivity ZIF Tip/Head (with N2803A) 112
N5441A 16 GHz Solder-In Head (with N2803A) 115
N5444A 28 GHz SMA 2.92 mm Head (with N2803A) 118
N5445A 30 GHz Browser Head, 1 mm span (with N2803A) 120
N5445A 30 GHz Browser Head, 2 mm span (with N2803A) 123
N5445A 30 GHz Browser Head, 3 mm span (with N2803A) 125

4
Contents

5
1
Using InfiniiMax III Series Probes
InfiniiMax III Probe Amplifiers 6
Proper Handling Techniques 9
InfiniiMax III and III+ Probing System Family Diagram 14
N5477A Sampling Scope Adapter 16
Cautions 17
SPICE Models for N5440A, N5447A, N5441A, N5445A, and N5444A Probe
Heads 18
SPICE Models for N2838A and N2836A Probe Heads 24
Simplified InfiniiMax III Schematic 27
This chapter contains documentation on using the InfiniiMax III probing
system.
The InfiniiMax III probing system offers you the highest performance
available for measuring differential and single-ended signals, with flexible
connectivity solutions for today’s high-density ICs and circuit boards. Four
different InfiniiMax III probe amplifiers ranging from 16 GHz to 30 GHz are
available for matching your probing solution to your performance and
budget requirements. A proprietary 200 GHz fT InP (indium phosphide) IC
process with backside ground vias and novel thick film technology is
utilized to accommodate your highest performance needs.
The family diagram for the InfiniiMax III probing system is shown in
“InfiniiMax III and III+ Probing System Family Diagram" on page 14. This
system is designed to give you the maximum flexibility in matching your
probe to your setup. The following pages will discuss each of the
adapters, probe amplifiers, and probe heads in detail.
CAUTION Refer to “Proper Handling Techniques" on page 9 before connecting any probe
to the oscilloscope.

6
1. Using InfiniiMax III Series Probes
InfiniiMax III Probe Amplifiers
InfiniiMax III Probe Amplifiers
There are four InfiniiMax III amplifier models:
• N2800A 16 GHz Probe Amplifier
• N2801A 20 GHz Probe Amplifier
• N2802A 25 GHz Probe Amplifier
• N2803A 30 GHz Probe Amplifier
Each probe amplifier is pre-loaded with its specific measured
S-parameters. When used with the Infiniium 90000 X-series, the
oscilloscope downloads these parameters and automatically corrects the
response of the unique probe system.
Figure 1 InfiniiMax III Probe Amplifier
Menu Button Press this button to bring up the Probe dialog box in the oscilloscope GUI.
Light Button Press this button to turn the LED headlights on the browser probe head
on/off. Pressing and holding this button will ramp the intensity of the LED
headlights. You may want to adjust the brightness to accommodate
different lighting or glare conditions.
Sensitivity Indicator If you are using the ZIF probe head, the sensitivity indicator tells you
which ZIF tip is connected to the probe head. If the N5447A ceramic high
sensitivity ZIF tip is connected then the “Hi” sensitivity LED will be
illuminated. If the N5440A ceramic ZIF tip is connected then the “Normal”
sensitivity LED will be illuminated. This will assist you in ensuring that the
correct ZIF tip is selected in the oscilloscope GUI’s probe dialog box.

7
1. Using InfiniiMax III Series Probes
InfiniiMax III Probe Amplifiers
CAUTION If you select the wrong pairing of ZIF probe head and ZIF probe tip in the
oscilloscope GUI’s probe menu, your waveforms will look incorrect.
DC Calibration Indicator Indicates if the particular combination of probe amplifier, probe head, and
oscilloscope channel input is calibrated. Any time you use a new probe
head type, a new probe amplifier, or a different channel on the
oscilloscope, the DC Cal indicator turns amber, indicating that a DC
calibration is required. After performing a calibration as described in
Chapter 4, “Calibration / Deskew Procedure”, the DC Cal indicator turns
green.
Channel Identification
Rings
Use the channel-identification rings to match each probe to the color of
the oscilloscope’s input channel to which it is connected. This enables you
to quickly know which probe is connected to each channel without having
to trace cables back to the oscilloscope inputs.
Channel Connection
CAUTION Refer to “Proper Handling Techniques" on page 9 before connecting any probe
to the oscilloscope.
The connector labeled A in Figure 1 on page 6 plugs into one of the
oscilloscope channel inputs. If connecting it directly to an Infiniium 90000
X-series oscilloscope, plug it into the channel and then turn the gray
clutch/dial around the input (Figure 2 on page 8) until it clicks. To
disconnect the probe amplifier, loosen the clutch on the oscilloscope
input and disconnect the probe amplifier. If you are using an InfiniiMax III
probe amplifier with a Keysight sampling oscilloscope, you will need to
use the N5477A sampling scope adapter.
The connector labeled B in Figure 1 on page 6 connects to one of the
InfiniiMax III probe heads.
CAUTION InfiniiMax I and II probe heads are not compatible with the InfiniiMax III probe
amplifiers and vice versa.

8
1. Using InfiniiMax III Series Probes
InfiniiMax III Probe Amplifiers
Figure 2 Clutches on an Infiniium 90000 X-series oscilloscope
NOTE The clutches on the Infiniium 90000 X-series do not require a mechanical
calibration. They will maintain the same tolerance as the Keysight torque wrench (8
in lbs ±1 in lbs).
Probe Amplifier
Bandwidth Upgrades
The InfiniiMax III probe amplifiers are upgradeable. When you order a
probe bandwidth upgrade, you receive a new probe with a new model
number and new serial number. The bandwidth upgrades are:
• N5446A-001 16 GHz to 20 GHz bandwidth upgrade
• N5446A-002 20 GHz to 25 GHz bandwidth upgrade
• N5446A-003 25 GHz to 30 GHz bandwidth upgrade
• N5446A-004 16 GHz to 25 GHz bandwidth upgrade
• N5446A-005 16 GHz to 30 GHz bandwidth upgrade
• N5446A-006 20 GHz to 30 GHz bandwidth upgrade

9
1. Using InfiniiMax III Series Probes
Proper Handling Techniques
Proper Handling Techniques
This guide will assist you in properly handling your InfiniiMax III
N2800A-series probes to prevent damage and maintain high
performance. For more safe-handling information, go to
www.keysight.com/find/scope-demo, click on See Keysight's probes in action,
and then InfiniiMax III ESD Best Practices demo video listed under the
Document Library tab.
CAUTION Electrostatic discharge (ESD) can quickly and imperceptibly damage or destroy
high-performance probes, resulting in costly repairs. Always wear a wrist strap
when handling probe components.
CAUTION Probes are sensitive devices and should be treated with care. Do not bend or kink
the probe amplifier cable. Do not drop heavy objects on the probe, drop the probe
from large heights, spill liquids on the probe, etc. Any of these examples can
significantly degrade the performance of the probe.
CAUTION When storing the probe, it is best to coil the cable in a large radius and avoid a net
twist in the cable during the process. This can be done in a similar manner to how
garden hoses or extension cords are typically coiled.
CAUTION InfiniiMax I and II probe heads cannot be used with InfiniiMax III probe amplifiers
and InfiniiMax III probe heads cannot be used with InfiniiMax I and II amplifiers.
CAUTION Never allow the probe head to be connected to the probe amplifier, if the probe
amplifier is not connected to the oscilloscope channel.
CAUTION Always disconnect an N5441A solder-in probe head from the probe amplifier before
unsoldering, moving to a new position, and resoldering the head.
Before Connecting a
Probe
InfiniiMax probes and accessories are ESD sensitive devices and should be
treated with care. Before using or handling the probe or accessories,
always wear a grounded ESD wrist strap and ensure that cables and
probe heads are discharged before being connected.
All work, including connecting probe amplifiers to the oscilloscope,
should be performed at a static-safe work station as shown in Figure 3 on
page 10.

10
1. Using InfiniiMax III Series Probes
Proper Handling Techniques
Figure 3 Static-Safe Work Station
Many scopes including Keysight's 90000X series have a front-panel
ground socket. You can plug the wrist strap into the ground socket as
seen in the following picture.
Figure 4 Wrist Strap Connected to Oscilloscope Ground Socket
The static-safe work station shown in Figure 3 uses two types of ESD
protection:
• Conductive table-mat and wrist-strap combination.
• Conductive floor-mat and heel-strap combination.
Both types, when used together, provide a significant level of ESD
protection. Of the two, only the table-mat and wrist-strap combination
provides adequate ESD protection when used alone. To ensure user

11
1. Using InfiniiMax III Series Probes
Proper Handling Techniques
safety, the static-safe accessories must provide at least 1 MΩof isolation
from ground. Purchase acceptable ESD accessories from your local
supplier.
WARNING These techniques for a static-safe work station should not be used when working
on circuitry with a voltage potential greater than 500 vol ts.
Connecting a Probe to
an Oscilloscope Channel
To protect against ESD damage, always use the following steps when
connecting your probe to the oscilloscope.
1If the Device Under Test (DUT) is not grounded to the oscilloscope via
the AC mains ground, connect the DUT ground to the oscilloscope
ground. An example of a device having a floating ground would be a
battery-powered DUT.
2Attach the probe head to the DUT.
CAUTION At this point, the N2800A-series probe amplifier must not be connected to the
oscilloscope or the probe head.
3Connect the probe amplifier to the oscilloscope while hand tightening
the dark gray clutch ring. The clutch ring limits the applied torque to 8
in-lb (±1 in-lb).
4Connect the probe head to the probe amplifier.

12
1. Using InfiniiMax III Series Probes
Proper Handling Techniques
CAUTION When connecting a probe head to a probe amplifier, push straight in. When
disconnecting a probe head from an amplifier, pull the probe head connectors
straight out of the sockets. Never bend the probe head in order to pry it loose from
the amplifier. Also, do not wiggle the probe head up and down or twist it to remove
the connectors from the sockets. This can damage the pins in the amplifier or the
probe head itself.
Disconnecting a Probe
from an Oscilloscope
Channel
Always disconnect the probe head from the probe amplifier before:
• disconnecting the probe amplifier from the oscilloscope.
• switching the probe amplifier from one oscilloscope channel to
another.
CAUTION Never allow the probe head to be connected to the probe amplifier, if the probe
amplifier is not connected to the oscilloscope channel.

13
1. Using InfiniiMax III Series Probes
Proper Handling Techniques
Figure 5 Probe Improperly Disconnected from Oscilloscope while Probe Head is
Connected to the Probe Amplifier
Probing the DUT When making your measurements, you’ll often need to probe different
locations on the DUT. You can safely move any of the following three
probe heads without having to first break the amplifier-to-head
connection:
• N5445A differential browser head
• N5439A ZIF head
• N5444A 2.92 mm/3.5 mm/SMA head
The only exception is when the DUT is not grounded to the oscilloscope
via the AC mains ground. In this case, connect the DUT ground to the
oscilloscope ground before moving the probe. An example of a device
having a floating ground would be a battery-powered DUT.
When probing with an N5441A solder-in probe head, always disconnect
the probe head from the amplifier before moving the head to a new
probing point. This is because some soldering-iron tips can hold a charge
which can damage the probe amplifier.
CAUTION Always disconnect an N5441A solder-in probe head from the probe amplifier before
unsoldering, moving to a new position, and resoldering the head.

14
1. Using InfiniiMax III Series Probes
InfiniiMax III and III+ Probing System Family Diagram
InfiniiMax III and III+ Probing System Family Diagram
The following diagram shows the InfiniiMax III and InfiniiMax III+ probes
and probe heads. The diagram is not drawn to scale.
Figure 6 InfiniiMax III / III+ Probing System
For extreme temperature testing, use the N5450B InfiniiMax extreme
temperature extension cable with the N5441A solder-in head. The
N5441A can withstand temperatures from –55°C to +150°C for up to 250
test cycles.

15
1. Using InfiniiMax III Series Probes
InfiniiMax III and III+ Probing System Family Diagram
CAUTION None of the N2800/1/2/3A probe amplifiers can withstand the extreme
temperatures (–55°C to +150°C) that the N5450B can withstand. When using the
N5450B extension cable, do not subject the InfiniiMax III probe amplifier to extreme
temperatures.
CAUTION None of the other probe heads are designed for extreme temperature testing.
The N5449A includes one N2873A probe. The adapter is specifically tuned
for the N2873A probe. Similar probes (1 ΜΩ input) can be used. Other
probes may not meet the bandwidth specification.
CAUTION When using the N5450B extension cable, do not subject the InfiniiMax III probe
amplifier or probe head (other than the N5441A solder-in probe head) to extreme
temperatures.
Use the N5443A Performance Verification (PV) accessory
fixture to properly position the probe for PV testing.

16
1. Using InfiniiMax III Series Probes
N5477A Sampling Scope Adapter
N5477A Sampling Scope Adapter
The N5477A Sampling Scope Adapter allows you to connect the
InfiniiMax III probing system to the Infiniium 86100D DCA-X sampling
oscilloscope or other RF instruments.
Figure 7 N5477A InfiniiMax III Sampling Scope Adapter
Connect the NMD/3.5 mm side of the adapter to one of the channel
inputs on the sampling oscilloscope. Then connect the power cord to
either the probe power output on the DCA-X 86100D wideband
oscilloscope (if the module being used has this receptacle) or to the
1143A power module. Finally, connect the other side of the adapter to the
InfiniiMax III probe amplifier.
Previously, the DCA-X wideband oscilloscope was limited to 13 GHz of
probing, but with the N5477A sampling oscilloscope adapter, the DCA-X
can now probe up to 30 GHz.
The N5477A sampling oscilloscope adapter can also be used to connect
the InfiniiMax III probing system to generic 50 Ohm test equipment as
long as the 1143A power supply and 5062-1247 NMD male-to-3.5mm
female adapter are used. Both of these parts can be ordered through
Keysight Technologies.

17
1. Using InfiniiMax III Series Probes
Cautions
Cautions
In addition to the CAUTION notices below, also refer to the CAUTION
notices listed in each section of this book.
CAUTION Electrostatic discharge (ESD) can quickly and imperceptibly damage or destroy
high-performance probes, resulting in costly repairs. Always wear a wrist strap
when handling probe components.
CAUTION Probes are sensitive devices and should be treated with care. Do not bend or kink
the probe amplifier cable. Do not drop heavy objects on the probe, drop the probe
from large heights, spill liquids on the probe, etc. Any of these examples can
significantly degrade the performance of the probe.
CAUTION Whenever you disconnect a probe head from an InfiniiMax amplifier, pull the probe
head connectors straight out of the sockets. When connecting a probe head to an
amplifier, push straight in also. Never bend the probe head in order to “pop” it loose
from the amplifier. Also, do not wiggle the probe head up and down or twist it to
remove the connectors from the sockets. This can damage the pins in the amplifier
or the probe head itself.
CAUTION When storing the probe, it is best to coil the cable in a large radius and avoid a net
twist in the cable during the process. This can be done in a similar manner to how
garden hoses or extension cords are typically coiled.
CAUTION InfiniiMax I and II probe heads cannot be used with InfiniiMax III probe amplifiers
and InfiniiMax III probe heads cannot be used with InfiniiMax I and II amplifiers.
CAUTION Always remove the probe head from the device under test (DUT) before
disconnecting the probe amp from the oscilloscope.

18
1. Using InfiniiMax III Series Probes
SPICE Models for N5440A, N5447A, N5441A, N5445A, and N5444A Probe Heads
SPICE Models for N5440A, N5447A, N5441A, N5445A, and
N5444A Probe Heads
These are SPICE models for the input impedances of the various InfiniiMax
III probes. Generic SPICE sub-circuit files are listed so they can be copied
and pasted into user’s SPICE simulations.
Chapter 6, “Performance Plots” shows the matching between the
measured input impedance and these modeled input impedances for the
various probe heads.
The following diagram shows the SPICE circuit used for these probe
heads:
• N5440A 28 GHz Ceramic ZIF Tips (with N5439A ZIF Probe Head)
• N5447A 28 GHz Ceramic High Sensitivity ZIF Tips (with N5439A ZIF
Probe Head)
• N5441A 16 GHz Solder-In Probe Head
• N5445A Browser Probe Head
• N5444A SMA Probe Head

19
1. Using InfiniiMax III Series Probes
SPICE Models for N5440A, N5447A, N5441A, N5445A, and N5444A Probe Heads
Figure 8 SPICE circuit to use for N5440A, N5447A, N5441A, N5445A, and
N5444A probe heads
The input impedance is only a function of the probe head; the amplifier
input does not significantly affect the input impedance.

20
1. Using InfiniiMax III Series Probes
SPICE Models for N5440A, N5447A, N5441A, N5445A, and N5444A Probe Heads
NOTE You’ll find the following SPICE data on the documentation CD that was shipped with
your probe. Copying this data from the CD is the simplest most reliable method to
get the data.
N5440A Ceramic ZIF Tip,
N5439A ZIF Probe Head
.subckt N5440A_N5439A_450ohmZIF 1 2
c1 1 10 20f
l1 10 11 1.5n
r1 11 2 180
rp1 1 3 180
lp1 3 4 1.5n
cp1 4 5 24f
cp2 5 6 100n
rp2 6 1 500
rp3 5 1 50k
cm1 2 7 24f
lm1 7 8 1.5n
rm1 8 5 180
cm2 2 9 100n
rm2 9 5 500
rm3 2 5 50k
rom 5 0 180
lom 5 0 30u
.ends
N5447A Ceramic High
Sensitivity ZIF Tip,
N5439A ZIF Probe Head
.subckt N5447A_N5439A_200ohmZIF 1 2
c1 1 10 20f
l1 10 11 2.3n
r1 11 2 250
rp1 1 3 1.2k
lp1 3 4 2.3n
cp1 4 5 24f
cp2 5 6 100n
rp2 6 1 250
rp3 5 1 25k
cm1 2 7 24f
lm1 7 8 2.3n
rm1 8 5 1.2k
cm2 2 9 100n
rm2 9 5 250
rm3 2 5 25k
rom 5 0 150
lom 5 0 30u
.ends