Keysight N2818 User manual

Keysight N2818/9A
Differential Probes
User’s Guide

2Keysight N2818/9A Differential Probes User Guide
Notices
© Keysight Technologies 2014, 2015, 2016,
2020
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Manual Part Number
N2818-97004
Edition
Edition 5, October 2020
Available in electronic format only
Published by:
Keysight Technologies
1400 Fountaingrove Parkway
Santa Rosa, CA, 95403
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Safety Notices
CAUTION
A CAUTION notice denotes a hazard.
It calls attention to an operating
procedure, practice, or the like that,
if not correctly performed or
adhered to, could result in damage
to the product or loss of important
data. Do not proceed beyond a
CAUTION notice until the indicated
conditions are fully understood and
met.
WARNING
A WARNING notice denotes a haz-
ard. It calls attention to an operat-
ing procedure, practice, or the like
that, if not correctly performed or
adhered to, could result in personal
injury or death. Do not proceed
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indicated conditions are fully
understood and met.

Keysight N2818/9A Differential Probes User Guide 3
Contents
Introduction 5
Oscilloscope Compatibility 6
Handling the Probe 6
Channel Identification Rings 7
To Clean the Probe 7
Inspecting the Probe 7
Accessories 8
N2818A 8
N2819A 10
Using the N2818A Probe 12
Connecting the Extreme Temperature Probing Kit to the Probe 13
Using the N2819A Probe 16
Single and Variable Pitch Signal Pins 17
Extension Leads 18
Micro IC Clips and Pincer Clips 18
DC Blocking Capacitor 18
Probe Offset Adjustment 19
Safety Information 21
Specifications and Characteristics 25
N2818A Performance Plots 28
N2819A Performance Plots 32
N2818A Performance Verification 36
Scope Vertical Accuracy 37
DC Differential Gain 37
Bandwidth 38

4Keysight N2818/9A Differential Probes User Guide
Contents
N2819A Performance Verification 40
Scope Vertical Accuracy 40
DC Differential Gain 41
Bandwidth 41
Returning the Probe for Service 44
Contacting Keysight Technologies 44
Index

Keysight N2818/9A Differential Probes
User Guide
Introduction
The N2818A and N2819A differential probes provide superior
general-purpose differential signal measurements that are required for
high-speed power measurements, vehicle bus measurements, and
high-speed digital system designs.
Table 1 Quick Probe Comparison
Figure 1 Probes (Accessories Not Shown)
CAUTION
Before using the probe, refer to “Safety Information" on page 21.
N2818A without N7013/14A
Extreme Temperature Probing
Kit
N2818A with N7013/14A
Extreme Temperature Probing
Kit
N2819A
Bandwidth 200 MHz 70 MHz 800 MHz
Attenuation Ratio 10:1 10:1 10:1
Input Resistance 1 MΩ1 MΩ200 kΩ
Input Capacitance 3.5 pF 3.5 pF 1 pF

6Keysight N2818/9A Differential Probes User Guide
Using the Probe
Oscilloscope Compatibility
The N2818A and N2819A probes are compatible with the Keysight
oscilloscopes shown in Table 2. Up to four probes can be connected to the
oscilloscope at the same time. The table also lists the minimum required
firmware version for the oscilloscope.
Is Your Oscilloscope Software Up-to-Date? Keysight periodically releases
software updates to support your probe, fix known defects, and
incorporate product enhancements. To download the latest firmware, go
to www.keysight.com and search for your oscilloscope’s topic. Click on the
“Drivers, Firmware & Software” tab.
Table 2 Compatible Oscilloscopes and Support
Handling the Probe
Handle the probe with care and refer to the safety notices in this manual.
Note that the probe cable and the extreme temperature extension cables
are sensitive parts and, therefore, you should be careful not to damage
them through excessive bending or pulling. You should also avoid any
mechanical shocks to this probe in order to guarantee accurate
performance and protection.
NOTE
The N2818A and N2819A probes are designed for oscilloscopes with
50ΩAutoProbe-interface channel inputs. The AutoProbe interface
provides the power to the probe.
Oscilloscope Required
Firmware Version
Adapter Required
Infiniium Oscilloscopes
90000 Q-Series ≥ 4.30 N5442A
90000 X-Series ≥ 4.30 N5442A
90000A ≥ 4.30 —
9000 H-Series ≥ 4.30 —
9000A-Series ≥ 4.30 —
InfiniiVision Oscilloscopes
4000 X-Series ≥ 3.20 —
3000 X-Series ≥ 2.35 —

Keysight N2818/9A Differential Probes User Guide 7
Using the Probe
Channel Identification Rings
When multiple probes are connected to the oscilloscope, use the channel
identification rings to associate the channel inputs with each probe. Place
one colored ring near the probe’s channel connector and place an identical
color ring near the probe head.
To Clean the Probe
Disconnect the probe from the oscilloscope and clean the probe with a soft
cloth dampened with a mild soap and water solution. Make sure that the
probe is completely dry before reconnecting it to an oscilloscope. Avoid
using abrasive cleaners and chemicals containing benzene or similar
solvents.
Inspecting the Probe
• Inspect the shipping container for damage.
Keep the damaged shipping container or cushioning material until the
contents of the shipment have been checked for completeness and the
probe has been checked mechanically and electrically.
• Check the accessories.
• If the contents are incomplete or damaged, notify your Keysight
Technologies Sales Office.
• Inspect the probe. If there is mechanical damage or defect, or if the
probe does not operate properly, notify your Keysight Technologies
Sales Office.
If the shipping container is damaged, or the cushioning materials show
signs of stress, notify the carrier as well as your Keysight Technologies
Sales Office. Keep the shipping materials for the carrier’s inspection. The
Keysight Technologies office will arrange for repair or replacement at
Keysight Technologies’ option without waiting for claim settlement.
CAUTION
Always wear an ESD wrist strap when working with active probes. Not
doing so can result in the probe becoming permanently damaged.

8Keysight N2818/9A Differential Probes User Guide
Using the Probe
Accessories
N2818A
Supplied Accessories
The N2818A probe comes with the accessories shown in Figure 2. These
accessories are not compatible with N2819A probes. Replacements can be
ordered with the N2792-68700 replacement kit. The quantity for each
accessory in the kit is the same as listed in Table 3 and originally provided
with the probe.
Figure 2 N2818A Supplied Accessories
Table 3 N2818A Supplied Accessories
WARNING
The measurement category of a combination of a PROBE ASSEMBLY and
an accessory is the lower of the measurement categories of the PROBE
ASSEMBLY and of the accessory.
Hook Clips (Qty. 2) Alligator Clips (Qty. 2) Offset Adjustment Tool (Qty. 1)
Accessory Qty
Hook Clip (Black) 1
Hook Clip (Red) 1
Alligator Clip (Black) 1
Alligator Clip (Red) 1
Offset Adjustment Tool 1

Keysight N2818/9A Differential Probes User Guide 9
Using the Probe
Optional Accessories
For extreme temperature probing, you can order the N7013/14A extreme
temperature probing kit separately. This extreme temperature probing kit is
not compatible with N2819A probes. The quantity for each accessory in
the kit is the same as listed in Table 4.
Figure 3 N2818A Optional Accessories (Extreme Temperature Probing Kit)
Table 4 N2818A Optional Accessories
Accessory Qty
Extreme Temperature Hook Tip Adapters (Black) 1
Extreme Temperature Hook Tip Adapters (Red) 1
Extreme Temperature Differential Extension Cables (Black) 1
Extreme Temperature Differential Extension Cables (Red) 1
Extreme Temperature Banana-to-Socketed Tip Adapters for connecting to 0.025”
square pins (Black)
1
Extreme Temperature Banana-to-Socketed Tip Adapters for connecting to 0.025”
square pins (Red)
1

10 Keysight N2818/9A Differential Probes User Guide
Using the Probe
N2819A
The N2819A probe comes with the accessories shown in Figure 4 and
listed in Table 5 on page 11. These accessories are not compatible with
N2818A probes. Replacements can be ordered with the N2793-68700
replacement kit. The quantity for each accessory in the kit is the same as
listed in the table and originally provided with the probe.
Figure 4 N2819A Supplied Accessories

Keysight N2818/9A Differential Probes User Guide 11
Using the Probe
Table 5 N2819A Supplied Accessories
Accessory Qty
Pincer Clip (red) 1
Pincer Clip (black) 1
Micro IC Clip (red) 1
Micro IC Clip (black) 1
Extension Lead, 0.8 mm J-P, 5 cm long (red) 1
Extension Lead, 0.8 mm J-P, 5 cm long (black) 1
Extension Lead, 0.8 mm J-P, 10 cm long (red) 1
Extension Lead, 0.8 mm J-P, 10 cm long (black) 1
Single Signal Pin, 8 mm long 6
DC Blocking Capacitor 2
Variable Pitch Pins 2
Offset Adjustment Tool 1

12 Keysight N2818/9A Differential Probes User Guide
Using the Probe
Using the N2818A Probe
Before you can use the N2818A probe, gently push the supplied hook clips
or alligator clips onto the probe leads as shown in Figure 5. Use the hook
clips to clamp onto smaller components and the alligator clips to clamp
onto thicker gauge devices.
Figure 5 Inserting the Supplied Clips
WARNING
Must be Grounded. Before making connections to the input
leads of this probe, ensure that the probe’s output connector is
attached to the channel input of the oscilloscope and the
oscilloscope is properly grounded.
CAUTION
To protect against electrical shock, use only the accessories supplied
with this probe or in the accessory kit.
CAUTION
This probe is to carry out differential measurements between two points
on the circuit under test. This probe is not for electrically insulating the
circuit under test and the measuring instrument.

Keysight N2818/9A Differential Probes User Guide 13
Using the Probe
Connecting the Extreme Temperature Probing Kit to the Probe
For extreme temperature probing, you can connect the N7013/14A
extreme temperature probing kit with the probe.
The N7013A extreme temperature probing kit includes:
• One pair of extreme temperature differential extension cables (black
and red)
• One pair of extreme temperature hook tip adapters (black and red)
• One pair of extreme temperature banana-to-socketed tip adapters for
connecting to 0.025” square pins (black and red)
The N7014A extreme temperature probing kit includes:
• One pair of extreme temperature banana-to-socketed tip adapters for
connecting to 0.025” square pins (black and red)
NOTE
The N7013/14A extreme temperature probing kit is not supplied with
the probe. You can order this kit separately.
CAUTION
Only the extension cables and the tip adapters provided with the cables
are rated to extreme temperatures. The differential probe, original
cables, and original accessories should not be exposed to extreme
temperatures. When probing with the extension cables the bandwidth
performance will be reduced, see Table 6 on page 25.

14 Keysight N2818/9A Differential Probes User Guide
Using the Probe
Perform the following steps to connect the N7013/14A extreme
temperature kit to the N2818A probe:
1 Connect the red and black extreme temperature differential extension
cables to the existing probe cables.
Figure 6 Connecting the Extreme Temperature Differential Extension Cables
2 Connect the red and black extreme temperature hook tip adapters to
the extreme temperature differential extension cables which are
already connected to the existing probe cables.
Figure 7 Connecting the Extreme Temperature Hook Tip Adapters

Keysight N2818/9A Differential Probes User Guide 15
Using the Probe
Or,
Connect the red and black extreme temperature banana-to-socketed tip
adapters to the extreme temperature differential extension cables which
are already connected to the existing probe cables.
Figure 8 Connecting the Extreme Temperature Banana-to-Socketed Tip Adapters

16 Keysight N2818/9A Differential Probes User Guide
Using the Probe
Using the N2819A Probe
Before using the N2819A probe, attach the supplied probing accessories
to connect the probe inputs to the circuit under test. Figure 9 shows the
options for connecting the supplied clips, leads, and pins. Gently press the
probing accessories into the end of the probe’s tip. A label on the probe tip
identifies the probe’s positive and negative leads.
Figure 9 Probe Clip, Lead, and Pin Connections
WARNING
Must be Grounded. Before making connections to the input leads
of this probe, ensure that the probe’s output connector is
attached to the channel input of the oscilloscope and the
oscilloscope is properly grounded.
CAUTION
To protect against electrical shock, use only the accessories supplied
with this probe or in the accessory kit.

Keysight N2818/9A Differential Probes User Guide 17
Using the Probe
Single and Variable Pitch Signal Pins
Insert the single signal pins into the probe tip as shown in Figure 10.
Directly probing with these pins results in the best possible signal integrity
when compared to the other probing accessories.
Figure 10 Signal Pins Inserted into the Probe Tip
Figure 11 shows the variable pitch pins inserted into the probe tip. Gently
rotate the pins to change the distance between the pins.
Figure 11 Variable Pitch Pins Inserted into the Probe Tip
CAUTION
This probe is designed to perform differential measurements between
two points on the circuit under test. This probe is not for electrically
insulating the circuit under test and the measuring instrument.
NOTE
The single signal pins are symmetrical. Either end of the pin may be
inserted into the probe tip.

18 Keysight N2818/9A Differential Probes User Guide
Using the Probe
Extension Leads
If the length of the pins is not adequate for your measurement setup or if
you need to use the pincer or micro IC clips, the extension leads can be
placed over the pins as shown below. The probe comes with both 5 cm and
10 cm long extensions leads.
Figure 12 Extension Leads on Probe
Micro IC Clips and Pincer Clips
Use the micro IC and pincer clips to probe miniature IC and components.
These clips attach to the end of the extension leads. Squeeze the lever on
the micro IC clips to extend the grasping jaws. Push the back of the pincer
clips to extend their connectors.
DC Blocking Capacitor
Use the DC blocking capacitor to block out unwanted DC components on
the input signal.
Figure 13 DC Blocking Capacitor Inserted into the Probe Tip

Keysight N2818/9A Differential Probes User Guide 19
Using the Probe
Probe Offset Adjustment
The N2818A/19A differential probes can be adjusted for zeroing out the
probe's offset voltage using the trimmer tool supplied with the probe.
Follow the procedure described below to perform the offset zero
calibration.
1 Connect the probe to an oscilloscope channel input. Turn on the
oscilloscope and wait for 20 minutes to allow the oscilloscope and
probe to warm up.
2 If the oscilloscope needs calibration, perform a user calibration before
the probe calibration.
3 Using the probe's connection accessories, short the + and - inputs
together.
4 Press Default setup and Autoscale of the oscilloscope.
5 Press the channel button for the probe and set the oscilloscope
channel to DC coupled mode.
6 Set the oscilloscope to Averaging mode (x8 or higher) to reduce
oscilloscope noise, if needed.
7 Set the vertical scale of the oscilloscope to 100 mV/div.
8 Using the offset adjustment tool that comes with the probe, adjust the
probe offset voltage to zero volts.
NOTE
Allow the oscilloscope and probe to warm up for 20 minutes before
performing the adjustment.

20 Keysight N2818/9A Differential Probes User Guide
Using the Probe
Figure 14 Location of the Offset Adjustment