Page 1
Keysight N2820/1A
High-Sensitivity
Current Probes
User’s Guide
Page 2
Notices
CAUTION
WARNING
© Keysight Technologies 2014, 2016-2018
No part of this manual may be reproduced in
any form or by any means (including electronic storage and retrieval or translation into
a foreign language) without prior agreement
and written consent from Keysight Technologies, Inc. as governed by United States and
international copyright laws.
Manual Part Number
N2820-97006
Edition
March 2018
Available in electronic format only
Published by:
Keysight Technologies
1900 Garden of the Gods Road
Colorado Springs, CO 80907 USA
Warranty
The material contained in this document is
provided “as is,” and is subject to being
changed, without notice, in future editions.
Further, to the maximum extent permitted by
applicable law, Keysight disclaims all warranties, either express or implied, with regard
to this manual and any information contained
herein, including but not limited to the
implied warranties of merchantability and fitness for a particular purpose. Keysight shall
not be liable for errors or for incidental or
consequential damages in connection with
the furnishing, use, or performance of this
document or of any information contained
herein. Should Keysight and the user have a
separate written agreement with warranty
terms covering the material in this document
that conflict with these terms, the warranty
terms in the separate agreement shall control.
Technology Licenses
The hardware and/or software described in
this document are furnished under a license
and may be used or copied only in accordance with the terms of such license.
U.S. Government Rights
The Software is "commercial computer software," as defined by Federal Acquisition Regulation ("FAR") 2.101. Pursuant to FAR
12.212 and 27.405-3 and Department of
Defense FAR Supplement ("DFARS")
227.7202, the U.S. government acquires
commercial computer software under the
same terms by which the software is customarily provided to the public. Accordingly,
Keysight provides the Software to U.S. government customers under its standard commercial license, which is embodied in its End
User License Agreement (EULA), a copy of
which can be found at
http://www.keysight.com/find/sweula. The
license set forth in the EULA represents the
exclusive authority by which the U.S. government may use, modify, distribute, or disclose
the Software. The EULA and the license set
forth therein, does not require or permit,
among other things, that Keysight:
(1) Furnish technical information related to
commercial computer software or commercial computer software documentation that is
not customarily provided to the public; or (2)
Relinquish to, or otherwise provide, the government rights in excess of these rights customarily provided to the public to use,
modify, reproduce, release, perform, display,
or disclose commercial computer software or
commercial computer software documentation. No additional government requirements beyond those set forth in the EULA
shall apply, except to the extent that those
terms, rights, or licenses are explicitly
required from all providers of commercial
computer software pursuant to the FAR and
the DFARS and are set forth specifically in
writing elsewhere in the EULA. Keysight shall
be under no obligation to update, revise or
otherwise modify the Software. With respect
to any technical data as defined by FAR
2.101, pursuant to FAR 12.211 and 27.404.2
and DFARS 227.7102, the U.S. government
acquires no greater than Limited Rights as
defined in FAR 27.401 or DFAR 227.7103-5
(c), as applicable in any technical data.
52.227-14 (June 1987) or DFAR
252.227-7015 (b)(2) (November 1995), as
applicable in any technical data.
Safety Notices
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.
A WARNING 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 personal
injury or death. Do not proceed
beyond a WARNING notice until the
indicated conditions are fully
understood and met.
2 N2820/1A User’s Guide
Page 3
Contents
1 General Information
Introduction 6
Accessories 10
Inspecting the Probe 12
Returning the Probe for Service 13
Safety Information 15
2
Making Measurements
Introduction 20
Quick Start 23
To Measure Battery-Powered Devices 31
To Measure Charge on an Infiniium Oscilloscope 32
To Measure Charge on an InfiniiVision Oscilloscope 34
To Simultaneously View Zoomed-In/Zoomed-Out Waveforms 36
To Make Measurements Without Interrupting Your DUT 39
To Determine Maximum Input Voltage and Current 44
Extreme Temperature Probing 46
Burden Voltage of N2822/4A Probe Heads 47
Dynamic Range 49
3
Using N2825A Probe Heads
To Manually Identify the R
To Identify the R
To Identify the R
To Add a Custom Internal R
4
Probe Calibration
To Calibrate the Probe on Infiniium Oscilloscopes 66
To Calibrate the Probe on InfiniiVision Oscilloscopes 70
5
Characteristics and Specifications
Current Range Graphs 78
Zoomed-In Input Voltage Range Versus Supply Voltage 80
Zoomed-In Input Current Range Versus Supply Voltage 81
N2820/1A User’s Guide 3
Resistance Using a Unique Name 54
SENSE
Resistance Using an ID Resistor 55
SENSE
Resistance 52
SENSE
Resistor 61
SENSE
Page 4
Contents
Dimensions 83
6
Performance Data Plots
N2820A Frequency Response 86
N2820A Common Mode Rejection Ratio 88
N2820A Step Response 89
N2820A Step Tracking 90
N2820A Input Impedance 92
Input Load Model 93
7
Performance Verification
Average Gain of Zoomed-In Channel 97
Average Gain of Zoomed-Out Channel 101
Performance Test Record 105
4 N2820/1A User’s Guide
Page 5
Keysight N2820/1A High-Sensitivity Current Probes
CAUTION
User’s Guide
1 General Information
Introduction / 6
Accessories / 10
Inspecting the Probe / 12
Returning the Probe for Service / 13
Safety Information / 15
The N2820A and N2821A high-sensitivity current probes allow you to measure AC
and DC currents from 50 μA to 5A. These high dynamic-range probes are
designed to be used on devices that have very tight geometry constraints. Since
these probes do not need to be degaussed and do not require frequent calibration,
you can focus on making your measurements. The probes accurately construct the
current waveform by measuring the voltage across either an internal or external
DUT-mounted R
resistor, which results in highly repeatable measurements.
SENSE
Before using the probe, refer to “Safety Information” on page 15.
Page 6
1 General Information
Introduction
Introduction
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.
The N2820A and N2821A probes are shipped in a case. When you
receive the probe, inspect it as described in “Inspecting the
Probe” on page 12.
Figure 1 shows the different components of the N2820A and
N2821A probes. The N2820A two-channel probe, with its two
internal, parallel differential amplifiers, provides simultaneous low
and high gain views. The N2821A also includes two amplifiers and
its main output can be switched between these two views. Before
using an N2820A probe, connect the secondary cable as described
in “Quick Start” on page 23. The N2821A single-channel probe
looks identical to the N2820A but does not include the secondary
cable. The accessories provided with the probes are shown in
Figure 2 on page 10.
Figure 1 Probe Parts Identification
6 N2820/1A User’s Guide
Page 7
General Information 1
CAUTION
NOTE
Introduction
Probes are ESD sensitive devices, particularly at the probe heads. Follow
standard ESD precautions when handling. Remove head accessories
when storing the probe.
Oscilloscope Compatibility The N2820A and N2821A probes are compatible with the Keysight
oscilloscopes shown in Table 1. The table also lists the minimum
required firmware version for the oscilloscope.
The N2820A and N2821A probes are designed for oscilloscopes with 1
MW AutoProbe-interface channel inputs.
N2820/1A User’s Guide 7
Page 8
1 General Information
Introduction
Table 1 Compatible Oscilloscopes with Number of Probes Supported
Number of Probes Supported
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.
Oscilloscope N2820A
Infiniium Oscilloscopes (firmware version 4.2 or above)
90000A, X-, and Q-Series not supported not supported
9000 H-Series 2a or 4
9000A-Series 2a or 4
InfiniiVision Oscilloscopes (6000 X firmware version 6.0 or above, 4000 X firmware version 3.10 or
above, 3000 X firmware version 2.30 or above)
6000 X-Series 2 or 4
4000 X-Series 2 or 4
3000 X-Series 2 2
2000 X-Series not supported not supported
2 Channel Probe
b
b
b
b
N2821A
1 Channel Probe
c
4
c
4
c
4
c
4
d
a Dual-Grid View available.
b If secondary cables are not connected.
c On four channel oscilloscope.
d Maximum of 2 probes on two or four channel oscilloscope.
Infiniium Dual-Grid View The N2820A probe provides two channel-input cables which allow
two simultaneous views of the current waveform: a high-gain
zoomed-in and a low-gain zoomed-out view. On Infiniium
oscilloscopes, both zoomed-in and zoomed-out waveforms can be
simultaneously displayed in dual-grid view, where each waveform
can be viewed in a different time span. To learn more about
dual-grid view, refer to “To Simultaneously View
Zoomed-In/Zoomed-Out Waveforms” on page 36. InfiniiVision
oscilloscopes do not support dual-grid views. The zoomed-in
channel has 500 kHz bandwidth and the zoomed-out channel has
8 N2820/1A User’s Guide
Page 9
General Information 1
NOTE
Introduction
3 MHz bandwidth. N2821A probes, having only one channel-input
cable, do not support the simultaneous display of zoomed-out and
zoomed-in views.
There is no upgrade available to convert an N2821A (1 channel) probe to
an N2820A (2 channel) probe.
Probe Heads The probe is supplied with the N2822A, N2824A, and N2825A
interchangeable R
heads include different R
user-defined head does not include an R
selected in situations when you want to use your own R
resistor that you have mounted on your DUT. To learn about
configuring and using the heads, refer to Chapter 2, “Making
Measurements”.
probe heads. The N2822A and N2824A
SENSE
resistor values. The N2825A
SENSE
resistor and is
SENSE
SENSE
Make-Before-Break (MBB)
Connectors
Channel Identification
Rings
Five Make-Before-Break (MBB) connectors are provided with the
probes. The MBB connectors allow you to quickly probe multiple
locations on your DUT without interrupting the circuit under test.
Refer to “To Make Measurements Without Interrupting Your
DUT” on page 39 for more information.
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.
N2820/1A User’s Guide 9
Page 10
1 General Information
Accessories
Accessories
Supplied Accessories The N2820A and N2821A probes come with the accessories shown
in Figure 2. To learn how to use these accessories, refer to
Chapter 2, “Making Measurements”.
Figure 2 Supplied Accessories
10 N2820/1A User’s Guide
Page 11
General Information 1
NOTE
Accessories
To ensure the display of accurate waveforms, always connect the
supplied ground lead when probing battery-powered devices, such as
mobile phones. Refer to “To Measure Battery-Powered Devices” on
page 31.
Replacement Accessories Table 2 shows the available replacement accessories and parts.
Table 2 Replacement Accessories
Model
Number
N2822A 20 mΩ R
N2824A 100 mΩ R
N2825A User-defined R
N2826A Replacement unsocketed sensor leads (22 AWG) 5
N2827A Secondary Cable for use with N2820A probe 1
N2828A Replacement MBB Headers 5
N2829A Replacement MBB Receptacles and socketed sensor leads
Description Quantity
Head 1
SENSE
Head 1
SENSE
Head 1
SENSE
(22 AWG)
5
N2820/1A User’s Guide 11
Page 12
1 General Information
Inspecting the Probe
Inspecting the Probe
• Inspect the shipping container for damage.
• Check the accessories.
• If the contents are incomplete or damaged, notify your Keysight
• Inspect the probe. If there is mechanical damage or defect, or if
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.
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.
Technologies Sales Office.
the probe does not operate properly or pass calibration tests,
notify your Keysight Technologies Sales Office.
12 N2820/1A User’s Guide
Page 13
Returning the Probe for Service
NOTE
NOTE
If the probe is found to be defective we recommend sending it to an
authorized service center for all repair and calibration needs.
Perform the following steps before shipping the probe back to
Keysight Technologies for service.
1 Contact your nearest Keysight sales office for information on
obtaining an RMA number and return address.
2 Write the following information on a tag and attach it to the
malfunctioning equipment.
• Name and address of owner
• Product model number (for example, N2820A)
• Product Serial Number (for example, MYXXXXXXXX)
• Description of failure or service required
Include probing and browsing heads if you feel the probe is not meeting
performance specifications or a yearly calibration is requested.
General Information 1
Returning the Probe for Service
3 Protect the probe by wrapping in plastic or heavy paper.
4 Pack the probe in the original carrying case or if not available use
bubble wrap or packing peanuts.
5 Place securely in sealed shipping container and mark container as
“FRAGILE”.
If any correspondence is required, refer to the product by serial number
and model number.
Contacting Keysight
Technologi es
N2820/1A User’s Guide 13
For technical assistance, contact your local Keysight Call Center.
• In the Americas, call 1 (800) 829-4444
• In other regions, visit http://www.keysight.com/find/assist
Page 14
1 General Information
Returning the Probe for Service
Before returning an instrument for service, you must first call the
Call Center at 1 (800) 829-4444.
14 N2820/1A User’s Guide
Page 15
Safety Information
WARNING
WARNING
General Information 1
Safety Information
This manual provides information and warnings essential for
operating this probe in a safe manner and for maintaining it in safe
operating condition. Before using this equipment and to ensure
safe operation and to obtain maximum performance from the
probe, carefully read and observe the following warnings, cautions,
and notes.
This product has been designed and tested in accordance with
accepted industry standards, and has been supplied in a safe
condition. The documentation contains information and warnings
that must be followed by the user to ensure safe operation and to
maintain the product in a safe condition.
Note the external markings on the probe that are described in this
document.
To avoid personal injury and to prevent fire or damage to this
product or products connected to it, review and comply with the
following safety precautions. Be aware that if you use this probe
assembly in a manner not specified, the protection this product
provides may be impaired.
N2820/1A User’s Guide 15
Use Only Grounded Instruments.
Do not connect the probe’s ground lead to a potential other than earth
ground. Always make sure the probe and the oscilloscope are grounded
properly.
Connect and Disconnect Properly.
Connect the probe to the oscilloscope and connect the ground lead to
earth ground before connecting the probe to the circuit under test.
Disconnect the probe input and the probe ground lead from the circuit
under test before disconnecting the probe from the oscilloscope.
Page 16
1 General Information
WARNING
WARNING
WARNING
WARNING
WARNING
WARNING
WARNING
WARNING
Safety Information
Observe Probe Ratings.
Do not apply any electrical potential to the probe input which exceeds
the maximum rating of the probe. Make sure to comply with the voltage
versus frequency derating curve found in this manual.
Keep Away From Live Circuits.
Avoid open circuitry. Do not touch connections or components when
power is present.
Indoor Use Only.
Do not operate in wet/damp environments. Keep product surfaces dry
and clean.
Do Not Operate With Suspected Failures. Refer to qualified service
personnel.
16 N2820/1A User’s Guide
Never leave the probe connected to a conductor while it is not connected
to an oscilloscope or voltage measuring instrument.
Do not use a probe which is cracked, damaged or has defective leads.
Do not install substitute parts or perform any unauthorized modification
to the probe.
Do not operate the probe or oscilloscope in the presence of flammable
gasses or fumes. Operation of any electrical instrument in such an
environment constitutes a definite safety hazard.
Page 17
General Information 1
WARNING
WARNING
CAUTION
NOTE
WARNING
WARNING
Safety Information
Do not use the probe or oscilloscope in a manner not specified by the
manufacturer.
Service instructions are for trained service personnel. To avoid
dangerous electric shock, do not perform any service unless qualified to
do so. Do not attempt internal service or adjustment unless another
person, capable of rendering first aid and resuscitation, is present.
The probe cable is a sensitive part of the probe and, therefore, you should
be careful not to damage it through excessive bending or pulling. Avoid
any mechanical shocks to this product in order to guarantee accurate
performance and protection.
Avoid, if possible, the proximity of other conductors which may create
noise.
N2820/1A User’s Guide 17
Concerning the Oscilloscope or Voltage Measuring Instrument to
Which the Probe is Connected
Whenever it is likely that the ground protection is impaired, you must
make the instrument inoperative and secure it against any unintended
operation.
If you energize the instrument by an auto transformer (for voltage
reduction or mains isolation), the ground pin of the input connector
terminal must be connected to the earth terminal of the power source.
Page 18
1 General Information
WARNING
WARNING
WARNING
Safety Information
Before turning on the instrument, you must connect the protective earth
terminal of the instrument to the protective conductor of the (mains)
power cord. The mains plug shall only be inserted in a socket outlet
provided with a protective earth contact. You must not negate the
protective action by using an extension cord (power cable) without a
protective conductor (grounding). Grounding one conductor of a
two-conductor outlet is not sufficient protection.
Only fuses with the required rated current, voltage, and specified type
(normal blow, time delay, etc.) should be used. Do not use repaired fuses
or short-circuited fuse holders. To do so could cause a shock or fire
hazard.
Capacitors inside the instrument may retain a charge even if the
instrument is disconnected from its source of supply.
18 N2820/1A User’s Guide
Page 19
Keysight N2820/1A High-Sensitivity Current Probes
User’s Guide
2 Making Measurements
Introduction / 20
Quick Start / 23
Step 1. Attach the Sensor Leads / 23
Step 2. Attach the Probe Head / 24
Step 3. Attach the Secondary Cable / 25
Step 4. Connect Probe to Scope / 26
Step 5. Configuring the Probe on Infiniium Oscilloscopes / 27
Step 6. Configuring the Probe on InfiniiVision Oscilloscopes / 29
To Measure Battery-Powered Devices / 31
To Measure Charge on an Infiniium Oscilloscope / 32
To Measure Charge on an InfiniiVision Oscilloscope / 34
To Simultaneously View Zoomed-In/Zoomed-Out Waveforms / 36
To Make Measurements Without Interrupting Your DUT / 39
Extreme Temperature Probing / 46
Burden Voltage of N2822/4A Probe Heads / 47
Dynamic Range / 49
In this chapter, you’ll learn how to connect the probe to the
oscilloscope and how to perform several measurements. The probe
accessories are very flexible and can be configured to match your
unique probing requirements regarding convenience versus
accuracy.
Refer to Chapter 3, “Using N2825A Probe Heads”, for additional
information regarding the N2822A, N2824A, and N2825A probe
heads.
Page 20
2 Making Measurements
CAUTION
Introduction
Introduction
The probes are supplied with three interchangeable R
SENSE
heads: N2822A, N2824A, and N2825A. To begin using the probe,
refer to “Quick Start” on page 23. Figure 3 on page 21 illustrates
the relative merits of using the three different heads with the
different sensor leads.
N2822A and N2824A
Probe Heads
The N2822A and N2824A heads include built-in internal R
resistors. Because the oscilloscope recognizes when these probes
are connected, the oscilloscope automatically knows the value of
the R
resistor when calculating measurements.
SENSE
Table 3 Description of Heads
Description N2822A N2824A
R
Resistor 20 mΩ 100 mΩ
SENSE
R
Tolerance ±1% ±1%
SENSE
Maximum Power Dissipation
Current Range 250 µA to 5A 50 µA to 2.2A
Added Benefit Smaller voltage drop (lower burden voltage). For higher sensitivity (ie. lower noise).
a Temperature coefficient is 20 ppm / °C
a
500 mW 500 mW
probe
SENSE
20 N2820/1A User’s Guide
N2825A
Probe Head
The maximum sensor resistor power rating is 500 mW. The maximum
acceptable average current for the N2822A is 5 A
.
A
rms
The N2825A user-defined head does not include an R
and N2824A is 2.2
rms
resistor
SENSE
and is selected in situations when you want to use your own
external DUT-mounted R
resistor. Chapter 3, “Using N2825A
SENSE
Probe Heads”, provides additional information on using the
N2825A head.
Page 21
Making Measurements 2
Introduction
Figure 3 Different Probing Connections With Relative Merit
N2820/1A User’s Guide 21
Page 22
2 Making Measurements
CAUTION
Introduction
Sensor Leads The probe heads do not come with the sensor leads soldered on
them. Instead, you must solder on the appropriate leads as
described in “Quick Start” on page 23.
Always wear an ESD wrist strap when working with active probes. Not
doing so can result in the probe becoming permanently damaged.
22 N2820/1A User’s Guide
Page 23
Quick Start
Making Measurements 2
Quick Start
Step 1.
Attach the Sensor Leads
The probe heads do not come with the leads soldered on them.
Instead, you must solder on one of the following types of sensor
leads to the probe head.
• Accessory un-socketed leads (22 AWG).
• Accessory socketed leads (22 AWG).
•Your own leads.
The socketed leads are designed to plug directly onto the following
items:
• Standard PC board headers with 2.54 mm (0.1”) contact-pitch
spacing.
• MBB accessory headers mounted on the PC board. You can
quickly snap the socketed lead on and off the MBB header. To
learn about the MBB accessory, refer to “To Make
Measurements Without Interrupting Your DUT” on page 39.
1 Position the sensor leads into the head’s access hole as shown in
Figure 4.
Figure 4 Placing the Leads into the Tip’s Access Hole
2 Flip the head as shown in Figure 5 and insert the leads up through
the PC board’s solder holes TP1 and TP2. Insert the RED (+) lead at
TP2 and the BLACK lead at TP1. Solder the leads in place.
N2820/1A User’s Guide 23
Page 24
2 Making Measurements
NOTE
Quick Start
Figure 5 Lead Positions on PC Board
Step 2.
Attach the Probe Head
Gently press the head into position on the probe amplifier while
carefully mating the connector as shown in Figure 6.
Figure 6 Attaching and Removing a Head from the Probe
Never apply excessive force when attaching the head. To remove a head,
pull the head straight off the probe in the direction shown.
24 N2820/1A User’s Guide
Page 25
Making Measurements 2
NOTE
NOTE
CAUTION
Quick Start
Do not remove the four head screws when removing the head.
You can safely change a probe head while the probe is connected to an
oscilloscope that is powered on.
If lead wires are attached, do not pull on the wires as this could damage
the head.
Step 3.
Attach the Secondary
Cable
This step is for N2820A two-channel probes only. N2821A probes
are not designed for use with the secondary cable and cannot be
upgraded.
• Gently snap the secondary cable into the probe amplifier as
shown in Figure 7.
Figure 7 Connecting the N2820A’s Secondary Cable
N2820/1A User’s Guide 25
Page 26
2 Making Measurements
NOTE
Quick Start
Step 4.
Connect Probe to Scope
1 Connect the probe to any available oscilloscope channel.
For N2820A probes always connect the primary cable first promptly
followed by the secondary cable. This enables the oscilloscope to
automatically associate the two inputs to the same probe. Figure 8 is an
example of connecting two N2820A probes to non-adjacent channel
inputs.
Figure 8 Example of Connecting Two N2820A Probes to the Oscillo-
scope
26 N2820/1A User’s Guide
Page 27
Step 5.
NOTE
NOTE
NOTE
Configuring the Probe on
Infiniium Oscilloscopes
Making Measurements 2
Quick Start
N2820A Probes. Although connecting the primary and secondary cables
to adjacent channels may reduce clutter, this is not a requirement. For
example, you could connect an N2820A’s primary cable to channel 2 and
its secondary cable to channel 4.
To ensure the display of accurate waveforms, always connect the
supplied ground lead when probing battery-powered devices. Refer to
“To Measure Battery-Powered Devices” on page 31.
2 If you are using an Infiniium oscilloscope, continue with “Step 5.
Configuring the Probe on Infiniium Oscilloscopes” on page 27.
3 If you are using an InfiniiVision oscilloscope, continue with “Step 6.
Configuring the Probe on InfiniiVision Oscilloscopes” on page 29.
1 On the oscilloscope, click the Setup > Probe Configuration menu
command to view the Probe Configuration dialog box.
For N2820A probes, the probe’s primary channel tab in the Probe
Configuration dialog box configures both the primary and secondary
channel. The secondary channel is listed on another tab but is not
controlled from that tab.
N2820/1A User’s Guide 27
Page 28
2 Making Measurements
NOTE
Quick Start
Figure 9 Probe Configuration Dialog Box (N2821A Probe)
2 Click the tab that represents the probe. In the case of N2820A
probes, the probe’s primary channel.
3 If you are using an N2821A probe, use the Primary Channel Output
field to configure the input channel as a zoomed-in or zoomed-out
channel.
4 If you are using an N2825A user-defined head, which uses a
DUT-mounted R
R
resistor in the User Def Head Resistance field.
SENSE
resistor, enter the resistance of the external
SENSE
The above step manually enters the N2825A’s associated external R
resistance. But, when using multiple R
resistors on your DUTs, you
SENSE
will find more convenient procedures in Chapter 3, “Using N2825A Probe
Heads”.
28 N2820/1A User’s Guide
SENSE
Page 29
Step 6.
NOTE
NOTE
Configuring the Probe on
InfiniiVision Oscilloscopes
Making Measurements 2
Quick Start
1 Press the front-panel channel key that is associated with the probe.
In the case of N2820A probes, the probe’s primary channel.
2 Press the Probe softkey.
3 If you are using an N2821A probe, press the Zoom-In softkey to
toggle between zoomed-in (blue selection box on softkey) or
zoomed-out (clear selection box) for the channel. This softkey is
shown at the bottom of Figure 10 on page 30.
4 If you are using an N2825A user-defined head, which uses a
DUT-mounted R
Figure 10 on page 30. Then, enter the resistance of the R
resistor that you are using.
resistor, press the R-Sense softkey, shown in
SENSE
SENSE
The above step manually enters the N2825A’s associated external R
resistance. But, when using multiple R
resistors on your DUTs, you
SENSE
SENSE
will find more convenient procedures in Chapter 3, “Using N2825A Probe
Heads”.
For N2820A probes, softkeys for the probe’s primary channel configure
both the primary and secondary channel. Unlike Infiniium oscilloscopes,
InfiniiVision oscilloscopes do not support the assigning of names to
identify N2825A/R
combinations.
SENSE
N2820/1A User’s Guide 29
Page 30
2 Making Measurements
Quick Start
Figure 10 R-Sense Entry Box
30 N2820/1A User’s Guide
Page 31
To Measure Battery-Powered Devices
NOTE
To Measure Battery-Powered Devices
When making measurements on a battery-powered (floating)
device, such as a mobile phone, always connect the supplied
ground lead between ground on your device and the probe’s
ground connector as shown in Figure 11. Simply snap the end of
the ground lead onto the probe’s connector. Without the ground
connection, the common mode voltage is not guaranteed to be
within the common mode range of the amplifiers.
Failure to connect the ground lead may result in inaccurate waveforms.
Making Measurements 2
Figure 11 Supplied Ground Lead on Device
N2820/1A User’s Guide 31
Page 32
2 Making Measurements
NOTE
To Measure Charge on an Infiniium Oscilloscope
To Measure Charge on an Infiniium Oscilloscope
A new measurement, Charge, is available on Infiniium oscilloscopes.
This measurement determines the total current consumption over
time with the results listed in Ampere-hours (Ah). For N2820A
probes, the measurement includes the area under the curve across
both zoomed-in and zoomed-out waveforms.
Figure 12 shows a Charge measurement with Zoom Mode applied
and zoom window gating enabled.
Always connect the ground lead when probing mobile phones, as
explained in “To Measure Battery-Powered Devices” on page 31.
Figure 12 Charge Measurement of Mobile Phone Current in Standby
State with Zoom Mode
32 N2820/1A User’s Guide
Page 33
To make a Charge
NOTE
NOTE
measurement
Making Measurements 2
To Measure Charge on an Infiniium Oscilloscope
1 Connect the probe. If an N2825A user-defined head is used, enter
the R
on Infiniium Oscilloscopes” on page 27.
2 If desired, click the oscilloscope’s Zoom button to turn on
zoom mode.
resistance as explained in “Step 5. Configuring the Probe
SENSE
With Zoom Mode turned on, you can use gating to show a reduced
zoom-window time span compared to the normal window. This is
indicated on the non-zoomed waveform by a white boundary-area box.
Zoom mode is a software only expansion and results in the same vertical
resolution and accuracy between the zoom and non-zoom waveforms.
3 Click Measure > Mixed > Charge (N282XA) to view the Enter
Measurement Info dialog box.
Figure 13 Enter Measurement Info Dialog Box
4 If Zoom Mode is turned on, select Gate to Zoom Window to enable a
reduced zoom-window time span. If Zoom Mode is turned off, this
field is not selectable (grayed out).
5 If more than one N2820/1A probe is connected in the oscilloscope,
the dialog box allows you to select the probe used for the
measurement.
N2820/1A User’s Guide 33
Page 34
2 Making Measurements
NOTE
To Measure Charge on an InfiniiVision Oscilloscope
To Measure Charge on an InfiniiVision Oscilloscope
A new measurement, Charge, is available on InfiniiVision
oscilloscopes. This measurement determines the total current
consumption over time with the results listed in Ampere-hours (Ah).
For N2820A probes, the measurement includes the area under the
curve across both zoomed-in and zoomed-out waveforms.
Figure 14 shows a Charge measurement.
Always connect the ground lead when probing mobile phones, as
explained in “To Measure Battery-Powered Devices” on page 31.
Figure 14 Full Screen Charge Measurement with Zoom Mode
34 N2820/1A User’s Guide
Page 35
To make a Charge
NOTE
NOTE
measurement
Making Measurements 2
To Measure Charge on an InfiniiVision Oscilloscope
1 Connect the probe. If an N2825A user-defined head is used, enter
the R
on InfiniiVision Oscilloscopes” on page 29.
2 If desired, click the oscilloscope’s Zoom button to turn on
zoom mode.
resistance as explained in “Step 6. Configuring the Probe
SENSE
With Zoom Mode turned on, you can use gating to show a reduced
zoom-window time span compared to the normal window. This is
indicated on the non-zoomed waveform by a non-shaded boundary-area
box.
Zoom mode is a software only expansion and results in the same vertical
resolution and accuracy between the zoom and non-zoom waveforms.
3 Press the front-panel Meas key.
4 Press the Type: softkey.
5 Select one of two measurements:
Charge - Full Screen. The Full Screen measurement
interval variation measures the value on all displayed
data points. For more information, refer to the
oscilloscope’s Help system.
Charge - N Cycles. The N Cycles measurement interval
variation measures the value on an integral number of
periods of the displayed signal. If less than three edges
are present, the measurement shows “No edges”. For
more information, refer to the oscilloscope’s Help
system.
6 If more than one N2820/1A probe is connected to the oscilloscope,
softkeys appear that allow you to specify the channel on which to
perform the measurement.
N2820/1A User’s Guide 35
Page 36
2 Making Measurements
NOTE
To Simultaneously View Zoomed-In/Zoomed-Out Waveforms
To Simultaneously View Zoomed-In/Zoomed-Out
Waveforms
When using an N2820A probe, zoomed-in and zoomed-out
waveforms can be simultaneously viewed on:
• 9000 H-Series Infiniium oscilloscopes, and
• 9000A Series Infiniium oscilloscopes
In dual-grid view (shown in Figure 15), the zoomed-out waveform
originates from the probe's low-gain amplifier, and the zoomed-in
waveform originates from the probe's high-gain amplifier. The
zoomed-in waveform has less noise and dynamic range than the
zoomed-out waveform.
Dual-Grid View is not supported in InfiniiVision oscilloscopes.
36 N2820/1A User’s Guide
Page 37
Making Measurements 2
To Simultaneously View Zoomed-In/Zoomed-Out Waveforms
Figure 15 Displayed Zoom Windows
On the display, the bounding-area box identifies the portion of the
Oscilloscope’s Zoom Mode
zoomed-out waveform that is displayed in the zoomed-in window.
This is shown in Figure 15. The bounding-area box does not
indicate waveform clipping.
If you’re familiar with the
oscilloscope’s Zoom Mode, you may
be interested to know that while
Zoom Mode uses software to expand
the zoomed-in waveform, dual-grid
view uses hardware amplification
applied by the probe’s high-gain
amplifier.
If the border of the bounding-area box is red, this indicates that
output clamping is active. When the border is white, output
clampling is disabled.
Dual-grid view allows simultaneous viewing of high sensitivity and
high dynamic-range inputs. One example of using dual-grid view is
to quickly identify and view a specific pulse and perform a DC
power measurement on that pulse.
To view only one window
1 Click Setup > Display to open the Display Setup dialog box.
2 In the Quantity field, select 1.
N2820/1A User’s Guide 37
Page 38
2 Making Measurements
NOTE
To Simultaneously View Zoomed-In/Zoomed-Out Waveforms
For best measurement results, click Setup > Acquisition and select one
of the High Resolution settings.
38 N2820/1A User’s Guide
Page 39
Making Measurements 2
To Make Measurements Without Interrupting Your DUT
To Make Measurements Without Interrupting Your DUT
The supplied Make-Before-Break (MBB) connectors allow you to
easily connect and disconnect your probe without interrupting the
Device-Under-Test (DUT). With the MBB connector you can
quickly probe multiple locations on your DUT without having to
solder or unsolder the leads. The MBB can be used with all R
probe heads including the N2825A user-defined probe head.
SENSE
Figure 16 Probing with MBB Connector on DUT
As shown in Figure 17 on page 40, MBB connectors consist of a
receptacle and header. A sensor lead with socket snaps onto the
receptacle. The header has two 0.025” square pins that are
soldered onto pads with 2.54 mm (0.1”) contact-pitch spacing.
N2820/1A User’s Guide 39
Page 40
2 Making Measurements
NOTE
To Make Measurements Without Interrupting Your DUT
Figure 17 Socketed Lead Snaps Onto the MBB Receptacle
To Use the MBB
Connector
1 Solder one or more headers onto your DUT.
2 Snap the sensor lead’s socket onto the receptacle.
Once attached to the receptacle, the socket cannot easily be removed
without deforming the receptacle. For information on ordering additional
socketed sensor leads, receptacles, and headers, refer to Table 2 on
page 11.
3 Repeatedly plug the lead with MBB receptacle onto different
headers as you probe your DUT.
40 N2820/1A User’s Guide
Page 41
Making Measurements 2
To Make Measurements Without Interrupting Your DUT
Figure 18 illustrates how the MBB connection changes as you
gently push the receptacle onto the header while using an
N2822/4A head. Figure 19 on page 43 shows the schematic when
using the MBB with an N2825A user-defined head.
N2820/1A User’s Guide 41
Page 42
2 Making Measurements
To Make Measurements Without Interrupting Your DUT
Figure 18 Connecting the MBB Connector with N2822/4A Head
42 N2820/1A User’s Guide
Page 43
Making Measurements 2
To Make Measurements Without Interrupting Your DUT
Figure 19 MBB Connector With N2825A User-Defined Head
To Download the Header
Gerber File
You can download a Gerber file from Keysight that defines many of
the parameters needed to design the PC board connection for the
MBB header. Gerber files can be imported into many PC board
layout applications. You can download this file using the following
URL: www.keysight.com/find/N2828A
For information on the physical dimensions of the MBB header and
MBB socket/receptacle, refer to Figure 40 on page 83.
N2820/1A User’s Guide 43
Page 44
2 Making Measurements
V
max. input
V
max. output
A
probe
------------------------
≤
I
max. input
V
max. output
A
probeRSENSE
×
------------------------ ------------
≤
To Determine Maximum Input Voltage and Current
To Determine Maximum Input Voltage and Current
The probe’s maximum input voltage and current values are derived
using the equations in this section. Exceeding these values may
result in the signal being clipped on the screen. To perform the
calculations, you need the probe’s maximum output voltage (linear
operation) and the Gain, which are documented in Chapter 5,
“Characteristics and Specifications” (Table 11 on page 77) and
listed here:
Maximum Output Voltage: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12V
A
(Zoom-In) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
probe
A
(Zoom-Out). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
probe
Maximum Input Voltage The maximum differential input voltage is given by the following
equation. For a zoomed-in signal, the maximum input voltage
would be 40 mV. For a zoomed-out signal, the maximum input
voltage would be 1.2 V.
Maximum Input Current The following equation gives the maximum input current:
The value of the R
installed on the probe:
N2822A probe head: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mΩ
N2824A probe head: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 mΩ
N2825A probe head: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .user defined
44 N2820/1A User’s Guide
resistor depends on the probe head that is
SENSE
Page 45
Making Measurements 2
To Determine Maximum Input Voltage and Current
For example, when using an N2824A probe head with a zoom-in
signal, the maximum input current would be 400 mA.
N2820/1A User’s Guide 45
Page 46
2 Making Measurements
NOTE
Extreme Temperature Probing
Extreme Temperature Probing
By constructing your own long sensor leads, you can use the
N2820/1A probes for extreme temperature probing, such as
monitoring a product in an environmental chamber. The following
two sensor lead examples provide accurate measurements:
• 6 feet of twisted-pair wire using two turns-per-inch. The DUT
should be grounded to the probe.
• 10 feet of shielded twisted-pair wire using two turns-per-inch.
Ground to the probe both the DUT and the shield.
Do not directly subject the probe amplifier, head, or cable to extreme
temperatures. The probe’s operating temperature range is 0°C to 40°C
(32°F to 104°F).
46 N2820/1A User’s Guide
Page 47
Burden Voltage of N2822/4A Probe Heads
V
burden
I
measuredRshunt
×=
NOTE
Burden Voltage of N2822/4A Probe Heads
When an N2822/4A head is used, the resistance of the head’s
connectors, sensor leads, and internal R
in series with the DUT’s circuit and current is flowing through the
probe head, as shown in Figure 20.
Therefore, a burden voltage (IR) is introduced into your circuit.
Burden voltages may affect the circuit and will tend to increase the
noise. Burden voltages do not affect the measurement. Table 2 on
page 11 lists the resistances added by various probing
components.
N2825A heads do not contribute a burden voltage as the current is not
flowing through the head.
Making Measurements 2
resistor is connected
SENSE
Figure 20 V
N2820/1A User’s Guide 47
Developed Across Probing Components
burden
Page 48
2 Making Measurements
Burden Voltage of N2822/4A Probe Heads
Table 4 Resistance Added by Head Components
Component Resistance Contribution
Sensor Leads Without Socket 20 mΩ
Sensor Leads With Socket 40 mΩ
MBB Header Only (Not Connected) 20 mΩ
MBB Header/Receptacle/Socket 40 mΩ
R
(N2822A Head) 20 mΩ
SENSE
R
(N2824A Head) 100 mΩ
SENSE
(Round Trip)
48 N2820/1A User’s Guide
Page 49
Dynamic Range
Making Measurements 2
Dynamic Range
The N2820A and N2821A probes provide a large dynamic
measurement range (>20,000:1 or 86 dB on the zoomed-in
channel) that allows you to observe both the entire current
waveform and extremely small current fluctuations. As shown in
Figure 21, you could simultaneously view a mobile phone’s 135 mA
receive current pulses and 2 mA idle current in the presence of 2A
transmit current pulses, with a single acquisition. When using
N2820A probes on Infiniium oscilloscopes, use the powerful new
dual-grid view as explained in “To Simultaneously View
Zoomed-In/Zoomed-Out Waveforms” on page 36.
Figure 21 Small Pulses in the Presence of Large Pulses
R
N2820/1A User’s Guide 49
Value and Dynamic
SENSE
Range
Since the N2820A probe has two outputs, each with a different
gain, dynamic range encompasses both channels while using a
single R
zoomed-in waveform can display about 50 µA and the zoomed-out
channel can display about 2.2A for a dynamic range of
approximately 93 dB:
value. For example, with a 100 mΩ R
SENSE
resistor, the
SENSE
Page 50
2 Making Measurements
93dB 20
2.2A
50 μA
--------------
log=
Dynamic Range
Effects Other Than
Dynamic Range
Channel Position on the
Screen
The value of the R
shown in Figure 35, “Current Range of N2822/4A Heads,” on
page 78. Using these two R
the dynamic range could be increased to 100 dB.
Selecting the proper R
between a value that is large enough to obtain accurate
measurements while small enough to avoid negatively affecting the
circuit under test. Increasing the resistance
• decreases the noise,
• increases sensitivity, and
• increases the burden voltage across the R
Decreasing the resistance will have the opposite effect.
This probe does not have voltage offset. Use the oscilloscope’s
position controls to adjust the location of the waveform on the
screen. Vertical scaling occurs about zero amperes.
resistor can range from 1 mΩ to 1 MΩ as
SENSE
values in different measurements,
SENSE
resistance is often a compromise
SENSE
resistor (IR).
SENSE
50 N2820/1A User’s Guide
Page 51
Keysight N2820/1A High-Sensitivity Current Probes
User’s Guide
3 Using N2825A Probe
Heads
To Manually Identify the R
On Infiniium Oscilloscopes / 52
On InfiniiVision Oscilloscopes / 53
To Identify the R
To Identify the R
To Add a Custom Internal R
The N2825A user-defined head is normally
selected in situations where a DUT-mounted
R
resistor is used. In this chapter, you’ll
SENSE
learn how to perform the following tasks, which
enables the oscilloscope to make accurate
measurements:
• On Infiniium oscilloscopes, assign a custom
name to the N2825A. This name identifies
the resistance of a specific DUT-mounted
R
.
SENSE
• Change the N2825A’s internal ID resistor. This resistor identifies the N2825A
with a specific DUT-mounted R
•If the R
SENSE
measurement needs, you can add an internal R
Resistance Using a Unique Name / 54
SENSE
Resistance Using an ID Resistor / 55
SENSE
values of the N2822A and N2824A probe heads do not meet your
Resistance / 52
SENSE
Resistor / 61
SENSE
SENSE
.
resistor to the N2825A.
SENSE
Page 52
3 Using N2825A Probe Heads
To Manually Identify the R
SENSE
Resistance
To Manually Identify the R
If you are using multiple, different DUT-mounted R
resistances, the following procedures show you how to enter the
resistance each time that you use the N2825A head with a new
R
.
SENSE
On Infiniium
Oscilloscopes
This method is used in “Step 5. Configuring the Probe on Infiniium
Oscilloscopes” on page 27 and is repeated here.
1 Click the Setup > Probe Configuration menu command to view the
Probe Configuration dialog box, shown in Figure 22.
SENSE
Resistance
SENSE
Figure 22 Infiniium Dialog Box With N2825A Heads
2 Click the tab that represents the probe. In the case of N2820A
probes, the probe’s primary channel.
52 N2820/1A User’s Guide
Page 53
Using N2825A Probe Heads 3
To Manually Identify the R
SENSE
Resistance
On InfiniiVision
Oscilloscopes
3 In the dialog box, enter the R
resistance in the User Def Head
SENSE
Resistance field.
This method is used in “Step 6. Configuring the Probe on
InfiniiVision Oscilloscopes” on page 29 and is repeated here.
1 Press the front-panel channel key that is associated with the probe.
In the case of N2820A probes, the probe’s primary channel.
2 Click the Probe softkey followed by the R-Sense softkey.
3 Enter the resistance of the R
resistor that you are using.
SENSE
N2820/1A User’s Guide 53
Page 54
3 Using N2825A Probe Heads
NOTE
To Identify the R
Resistance Using a Unique Name
SENSE
To Identify the R
SENSE
Resistance Using a Unique Name
This procedure is for Infiniium oscilloscopes, only. InfiniiVision
oscilloscopes do not support the assigning of names to identify
N2825A/R
This procedure allows you to identify the external DUT-mounted
R
by a unique name. After completing the procedure, simply
SENSE
connect the probe with the N2825A probe head, and select the
unique name on the oscilloscope. The proper R
for the measurements. Selecting a unique name is easier than
manually entering the R
N2825A head with a new R
1 Click the Setup > Probe Configuration menu command to view the
Probe Configuration dialog box.
2 Use the Add Head field to assign a unique name for each of your
N2825A/R
3 Each time that you connect the probe, select the appropriate name
in the dialog box.
combinations.
SENSE
SENSE
resistance associations.
SENSE
value is used
SENSE
resistance each time that you use the
.
SENSE
54 N2820/1A User’s Guide
Page 55
To Identify the R
CAUTION
Using N2825A Probe Heads 3
Resistance Using an ID Resistor
SENSE
To Identify the R
SENSE
Resistance Using an ID Resistor
By changing the N2825A’s internal ID resistor, the probe head can
automatically indicate to the oscilloscope the value of the
DUT-mounted R
being used. Up to five dedicated N2825A
SENSE
probe heads can be configured in this manner using the ID resistor
values shown in Table 6.
Table 5 Valid N2825A ID Resistors
Resistor
Value
16.2 kΩ Default value. Resistor, ±1%, 0.063W, TC±100 thick film 0402 SMT
19.6 kΩ Resistor, ±1%, 0.063W, TC±100 thick film 0402 SMT
26.1 kΩ Resistor, ±1%, 0.063W, TC±100 thick film 0402 SMT
42.4 kΩ Resistor, ±1%, 0.063W, TC±100 thick film 0402 SMT
61.9 kΩ Resistor, ±1%, 0.063W, TC±100 thick film 0402 SMT
Description
For example, you might install a 19.6 kΩ ID resistor in one N2825A
to identify measurements using a 50 mΩ R
and a 26.2 kΩ ID
SENSE
resistor in another N2825A to identify measurements using a
300 mΩ R
. The first time that you use the modified N2825A,
SENSE
you must perform a one-time entry of the associated R
resistance on the oscilloscope. For subsequent uses, the
oscilloscope automatically uses the specified R
value for each
SENSE
N2825A head. You can order additional N2825A heads from
Keysight.
SENSE
N2820/1A User’s Guide 55
In the following procedure, always wear an ESD wrist strap and work at a
static-safe workstation. Not doing so can result in the probe head
becoming permanently damaged.
Page 56
3 Using N2825A Probe Heads
To Identify the R
Resistance Using an ID Resistor
SENSE
1 Remove the probe head by gently pulling the head straight off the
probe in the direction shown.
Figure 23 Removing the Probe Head
2 Remove the four hex screws that secure the cover of the N2825A
R
head and remove the cover.
SENSE
Figure 24 Removing the N2825A Cover
3 Remove the PC board from the head.
56 N2820/1A User’s Guide
Page 57
Using N2825A Probe Heads 3
CAUTION
To Identify the R
Figure 25 Remove PC Board
4 On the reverse side of the PC board, locate ID resistor, R2, as
shown in Figure 26.
Resistance Using an ID Resistor
SENSE
N2820/1A User’s Guide 57
Figure 26 Location of ID Resistor (R2)
5 Replace the ID resistor with any of the values listed in Table 7. The
default value loaded on the board is 16.2 kΩ. You can purchase a
resistor from a supplier such as Digi-Key corporation.
If you are not skilled in soldering, ask a trained assembler to change the
resistor.
Page 58
3 Using N2825A Probe Heads
CAUTION
To Identify the R
Resistance Using an ID Resistor
SENSE
Table 6 Valid N2825A ID Resistors
Resistor
Value
16.2 kΩ Default value. Resistor, ±1%, 0.063W, TC±100 thick film 0402 SMT
19.6 kΩ Resistor, ±1%, 0.063W, TC±100 thick film 0402 SMT
26.1 kΩ Resistor, ±1%, 0.063W, TC±100 thick film 0402 SMT
42.4 kΩ Resistor, ±1%, 0.063W, TC±100 thick film 0402 SMT
61.9 kΩ Resistor, ±1%, 0.063W, TC±100 thick film 0402 SMT
Description
6 Replace the N2825A’s cover using the four screws. (M1.6 x 0.35,
5 mm long, Keysight part number 0515-5210)
To avoid damaging the aluminum casting, do not over tighten the screws.
7 Connect the N2825A to an N2820/1A probe and connect the probe
to the oscilloscope.
8 On Infiniium oscilloscopes,
58 N2820/1A User’s Guide
a Click the Setup > Probe Configuration menu command.
b Select the tab for the probe’s primary channel. N2821A probes
only have a primary channel.
c In the User Def Head Resistance field, enter the resistance of the
DUT’s R
resistor in ohms.
SENSE
d In the dialog box, click Add Head to give your head with
associated external R
resistor a unique name.
SENSE
Page 59
Using N2825A Probe Heads 3
NOTE
To Identify the R
9 On InfiniiVision oscilloscopes,
a Press the front-panel channel key that is associated with the
probe’s primary input.
b Click the Probe softkey.
c Press the R-Sense softkey and enter the resistance of the R
resistor that you are using.
10 For future reference, mark your different N2825A heads using a
marker pen or tape and record the information in Table 7 on
page 60. In the table’s fourth column, record the name that you
entered in the Probe Configuration dialog box.
Resistance Using an ID Resistor
SENSE
SENSE
Remember to mark your different N2825A heads, using a marker pen or
tape, so that you can distinguish between them.
N2820/1A User’s Guide 59
Page 60
3 Using N2825A Probe Heads
To Identify the R
Resistance Using an ID Resistor
SENSE
Table 7 N2825A Identification
N2825A
Marking
Associated DUT R
Resistor Value
SENSE
ID Resistor
Value
Probe Name Registered
on the Oscilloscope
60 N2820/1A User’s Guide
Page 61
Using N2825A Probe Heads 3
NOTE
CAUTION
WARNING
To Add a Custom Internal R
SENSE
Resistor
To Add a Custom Internal R
If you need to use a different R
N2822A and N2824A heads, you can convert an N2825A head to
an internal R
400 mΩ internal R
the N2824A has a 100 mΩ R
400 mΩ R
Do not change the RSENSE resistor in N2822A or N2824A heads.
Always wear an ESD wrist strap when working with active probes. Not
doing so can result in the probe becoming permanently damaged.
1 Select a resistor of type ±1%, 0.5W, TC ±600, thick film 2010 SMT.
The value of the precision resistor can range from 1 mΩ to 1 MΩ in
1 mΩ increments.
SENSE
SENSE
SENSE
into an N2825A probe head.
Resistor
resistance than provided by the
SENSE
head. For example, suppose that you require a
, but the N2822A has a 20 mΩ R
SENSE
. You simply need to install your
SENSE
SENSE
and
N2820/1A User’s Guide 61
When selecting the resistance value, you must observe the 500 mW
maximum power rating of the head.
2 Remove the probe head by gently pulling the head straight off the
probe in the direction shown.
Page 62
3 Using N2825A Probe Heads
To Add a Custom Internal R
Resistor
SENSE
Figure 27 Removing the Probe Head
3 Remove the four hex screws that secure the head’s cover and
remove the cover.
Figure 28 Removing the Cover
4 Change or add the R
resistor (R1) as shown in Figure 29.
SENSE
62 N2820/1A User’s Guide
Page 63
Using N2825A Probe Heads 3
CAUTION
CAUTION
To Add a Custom Internal R
SENSE
Resistor
If you are not skilled in soldering, ask a trained assembler to change the
resistor.
Figure 29 Location of R
5 Replace the head’s cover using the four screws. (M1.6 x 0.35, 5 mm
long, Keysight part number 0515-5210)
Resistor (R1)
SENSE
To avoid damaging the aluminum casting, do not over tighten the screws.
6 Connect the N2825A to an N2820/1A probe and connect the probe
to the oscilloscope.
7 On Infiniium oscilloscopes,
a Click the Setup > Probe Configuration menu command.
b Select the tab for the probe’s primary channel. N2821A probes
only have a primary channel.
c In the User Def Head Resistance field, enter the resistance of the
DUT’s R
d In the dialog box, click Add Head to give your head with
associated external R
resistor in ohms.
SENSE
resistor a unique name.
SENSE
N2820/1A User’s Guide 63
Page 64
3 Using N2825A Probe Heads
To Add a Custom Internal R
Resistor
SENSE
8 On InfiniiVision oscilloscopes,
a Press the front-panel channel key that is associated with the
probe’s primary input.
b Click the Probe softkey.
c Press the R-Sense softkey and enter the resistance of the R
resistor that you are using.
You could also change the head’s internal ID resistor as explained
“To Identify the R
Resistance Using an ID Resistor” on
SENSE
page 55.
SENSE
64 N2820/1A User’s Guide
Page 65
Keysight N2820/1A High-Sensitivity Current Probes
CAUTION
User’s Guide
4 Probe Calibration
This chapter provides procedures for calibrating the probe on an Infiniium
oscilloscope and on an InfiniiVision Oscilloscope.
“To Calibrate the Probe on Infiniium Oscilloscopes” on page 66
“To Calibrate the Probe on InfiniiVision Oscilloscopes” on page 70
Always calibrate the probe before making any critical measurements. A probe
calibration removes attenuation, offset, and gain errors as well as timing delays
that are introduced by the probe. The calibration applies to a specific probe
(identified by serial number) that is connected to a specific oscilloscope channel. If
you connect the probe to a different channel, the calibration will no longer be
valid.
Always wear an ESD wrist strap when working with active probes. Not
doing so can result in the probe becoming permanently damaged.
Page 66
4 Probe Calibration
NOTE
To Calibrate the Probe on Infiniium Oscilloscopes
To Calibrate the Probe on Infiniium Oscilloscopes
During this calibration, you may be prompted to make one or more
adjustments. These adjustments, located on the underside of the
probe amplifier, are shown in Figure 32 on page 69.
Table 8 Required Calibration Test Equipment
Test Equipment Description
Procedure
N2825A User-Defined
Probe Head
Pomona 3788 BNC
Female to Minigrabber
Test Clips Breakout
Adapters SMA, BNC, BNC Tee, BNC cables and cable clips as needed.
Screwdriver For making adjustments during the procedure. This tool is
Provided with probe.
Refer to
http://www.pomonaelectronics.com/
for more information and how to order
this product.
provided with the probe.
Redirecting the Probe Comp Signal
On 9000-series and S-series Infiniium oscilloscopes, you can redirect
the Probe Comp signal to the Aux Output BNC connector on the rear
panel of the oscilloscope. This connector can then be connected to the
Pomona 3788 using a BNC cable. Click Utilities > Calibration and select
Probe Comp in the Aux Output drop-down list.
1 Turn the oscilloscope on.
2 Solder the sensor leads onto the N2825A user-defined head as
explained in “Quick Start” on page 23.
3 Attach the N2825A user-defined head to the probe.
66 N2820/1A User’s Guide
Page 67
Probe Calibration 4
N2820A Probe
N2825A Probe Head
Black Test Clip of
Pomona 3788
BNC Tee
BNC
Cable
BNC
Cable
Red Test Clip of
Pomona 3788
Pomona 3788
To Calibrate the Probe on Infiniium Oscilloscopes
4 Connect the equipment as shown in Figure 30 on page 67. Observe
the following requirements:
• Connect the probe to the scope channel that you will use during
probing. Use any other available scope channel for the BNC
cable that is needed for connection to the Pomona 3788.
• Connect the Pomona 3788 to two BNC cables using a BNC tee.
Then connect one of these BNC cables to a scope channel and
the other BNC cable to the Aux Output BNC connector located
on the Oscilloscope’s rear-panel (as shown in Figure 30).
• On N2820A probes, do not connect the secondary cable at this
time.
• Connect both the N2825A’s sensor leads (red and black wires) to
the black test clip of the Pomona 3788 as shown in Figure 30.
N2820/1A User’s Guide 67
Figure 30 Example of Initial Calibration Setup
Page 68
4 Probe Calibration
Red Wire connected
Red Test Clip of to the
Pomona 3788
Black Wire connected
Black Test Clip of to the
Pomona 3788
To Calibrate the Probe on Infiniium Oscilloscopes
5 Let the probe warm up for 15 minutes.
6 On the oscilloscope, click Setup > Channel to open the Channel
Setup dialog box and select the channel tab for the connected
probe.
7 Click Probes… to open the Probe Setup dialog box. Then, click the
Calibrate Probe… button.
8 Follow the steps that are displayed on the oscilloscope. For the
Gain Calibration step, connect the N2825A’s sensor leads (red and
black wires) as shown in Figure 31. The black wire should connect
to the black test clip of the Pomona 3788 and the red wire should
connect to the red test clip of the Pomona 3788.
68 N2820/1A User’s Guide
Figure 31 Example of Setup for the Gain Calibration Step
9 If you are prompted to make an adjustment, refer to Figure 32. The
adjustments are located on the underside of the probe amplifier.
Page 69
Probe Calibration 4
NOTE
To Calibrate the Probe on Infiniium Oscilloscopes
The screwdriver provided with the probe is the preferred adjustment tool.
Figure 32 Location of Calibration Adjustments
N2820/1A User’s Guide 69
Page 70
4 Probe Calibration
To Calibrate the Probe on InfiniiVision Oscilloscopes
To Calibrate the Probe on InfiniiVision Oscilloscopes
The following test equipment are needed for the calibration
procedure.
Table 9 Required Calibration Test Equipment
Test Equipment Description
Calibration Procedure
1. Connect the probe to the oscilloscope
N2825A User-Defined
Probe Head
Pomona 3781-12-2 Red
Minigrabber Test Clip
Patch Cord
Pomona 3781-12-0 Black
Minigrabber Test Clip
Patch Cord
Provided with probe.
Refer to
http://www.pomonaelectronics.com/ for
more information and how to order this
product.
Refer to
http://www.pomonaelectronics.com/ for
more information and how to order this
product.
a Turn the oscilloscope on.
b Plug the primary channel of the N2820A probe into the
oscilloscope channel you are intending to use.
c If applicable, plug the secondary channel of the probe into the
oscilloscope channel you are intending to use.
d Configure the zoomed-in path to the primary or secondary
channel as necessary.
e Solder the sensor leads onto the N2825A user-defined head as
explained in “Quick Start” on page 23.
f Attach the N2825A user-defined head to the probe.
70 N2820/1A User’s Guide
Page 71
To Calibrate the Probe on InfiniiVision Oscilloscopes
NOTE
Pomona 3781-12-2
N2825A Sensor Leads
connected to oscilloscope’s
Pomona 3781-12-2
connected to N2825A
sensor leads
Ground lug
N2825A Probe Head
Allow the oscilloscope and probe to warm up for at least
20 minutes before performing the probe calibration.
2. Manually adjust the probe’s initial offset
Calibration fails if the probe has too much initial offset. The
probe’s offset can be zeroed manually using the following
procedure.
a In the probe configuration menu, select 1Ω as the
N2825A probe head.
b Connect both the N2825A’s sensor leads (red and black wires) to
one end of the Pomona 3781-12-2 patch cord. Connect the
other end of this patch cord to the oscilloscope’s ground lug on
the front panel. A sample setup is displayed below.
Probe Calibration 4
R
for the
SENSE
N2820/1A User’s Guide 71
Figure 33 Probe Calibration Terminals Connections on an InfiniiVi-
sion-Series Oscilloscope
c Set up the oscilloscope as follows:
i) Set the time/div to 100 us/div.
Page 72
4 Probe Calibration
NOTE
To Calibrate the Probe on InfiniiVision Oscilloscopes
ii) Turn on Averaging with 16 averages.
iii) For both channels, set the V/div as small as possible to fit the
waveform on screen. For the zoomed-in channel, this should be
less than 10μA. For the zoomed-out channel, this should be less
than 2mA. If the waveform is not on screen at these settings,
increase the V/div and adjust the offset until these settings can
be used.
iv) Turn on Vavg measurements for both channels.
d To set the zoomed-out offset, turn R2 using the supplied
screwdriver until the Vavg measurement is +/- 1mA.
e To set the zoomed-in offset, turn R4 using the supplied
screwdriver until the Vavg measurement is +/- 1mA.
The R2 and R4 adjustments are located on the underside of the probe
amplifier as displayed in Figure 34. The screwdriver provided with the
probe is the preferred adjustment tool.
Figure 34 Location of Calibration Adjustments
f Press the Channel on/off key to turn the channel on (if the
channel is off).
72 N2820/1A User’s Guide
Page 73
3. Initiate Calibration
NOTE
a In the Channel menu, press the Probe softkey.
When you connect the probe, the Calibrate Probe softkey in the Channel
Probe menu becomes active.
b Press the Calibrate Probe softkey and then press the OK softkey to
begin calibration.
Probe Calibration 4
To Calibrate the Probe on InfiniiVision Oscilloscopes
N2820/1A User’s Guide 73
Page 74
4 Probe Calibration
To Calibrate the Probe on InfiniiVision Oscilloscopes
74 N2820/1A User’s Guide
Page 75
Keysight N2820/1A High-Sensitivity Current Probes
User’s Guide
5 Characteristics and
Specifications
Current Range Graphs / 78
Zoomed-In Input Voltage Range Versus Supply Voltage / 80
Zoomed-In Input Current Range Versus Supply Voltage / 81
Dimensions / 83
This chapter provides the characteristics and specifications for the N2820A and
N2821A probes. The probe should be warmed up for at least 20 minutes before
any testing and the environmental conditions should not exceed the probe’s
specified limits.
Table 10 Characteristics and Specifications
Item Characteristic
Bandwidth (–3 dB) Zoom-Out Channel: DC to 3 MHz
Zoom-In Channel: DC to 500 kHz
Risetime (Tr = 0.35/BW, 10% – 90%) Zoom-Out Channel: < 0.116 µs
Zoom-In Channel: < 0.7 µs
Minimum Measurable Current 250 µA (with N2822A 20 mΩ,)
50 µA (with N2824A 100 mΩ,)
5 mA (with N2825A user defined 1 mΩ,)
100 nA (with N2825A user defined 1 kΩ,)
Maximum Measurable Current 5A (with N2822A 20 mΩ, 500 mW)
2.2A (with N2824A 100 mΩ, 500 mW)
5A (with N2825A, 1 mΩ installed)
1.2 mA (with N2825A user defined 1 kΩ,)
a
Page 76
5 Characteristics and Specifications
Item Characteristic
Output Voltage Rate Zoom-In Channel: 6 V/A (with N2822A 20 mΩ)
Maximum Input Voltage ±12V
Maximum Output Voltage (Linear Operation) 12V
Burden Voltage (voltage drop on R
Dynamic Range 20,000:1, 86 dB (N2820A)
Oscilloscope Input Impedance 1 MΩ
Input Impedance 1.5 GΩ single ended
Gainc (warranted specification) Zoom-In: 300 ±3%
Noise, AC
rms
Sensor Resistor Accuracy ±1% (N2822A, N2824A)
Sensor Resistor Power Rating 500 mW (N2822A, N2824A)
Temperature Coefficient of Sensor Resistor < 20 ppm/°C
) Measured current * R
SENSE
30 V/A (with N2824A 100 mΩ)
Zoom-Out Channel: 0.04 V/A (with N2822A 20 mΩ)
0.2 V/A (with N2824A 100 mΩ)
<=15 Volts (maximum non destructive input voltage)
b
SENSE
1,000:1, 60 dB (N2821A)
3.0 GΩ differential
Zoom-Out: 1.97 ±3%
150 µA (with N2822A 20 mΩ, (hi res mode on) d
240 µA (with N2822A 20 mΩ, (hi res mode off)
30 µA (with N2824A 100 mΩ, (hi res mode on)
50 µA (with N2824A 100 mΩ, (hi res mode off)
d
Cable Lengths Sensor leads: 16 cm
aProbe loading (1.5GΩ) contributes 3% error at V
Probe cable: 1.2m
equal to 5V.
supply
b Clipping occurs for higher voltages, which may appear on the screen.
c Denotes warranted spec after 20 minute warm up. All others entries in the table are characteristics.
d With scope with high resolution mode on, sampling rate < 2.5 MSa/s, 20 MHz low-pass filter on.
76 N2820/1A User’s Guide
Page 77
Characteristics and Specifications 5
Table 11 Environmental Characteristics
Item Characteristic
Temperature (operating) Operating: 0° C to 40° C
Humidity (operating) Operating: tested at 95% RH @ +40° C
ESD 8 kV HBM
Indoor Use This probe is rated for indoor use only
Non-Operating: –40° C to 70° C
Non-Operating: tested at 90% RH, +65° C
Table 12 Compatible Oscilloscopes
InfiniiVision Oscilloscopes
3000 X-Series (with software version 2.30 or higher)
4000 X-Series (with software version 3.10 or higher)
Infiniiuma Oscilloscopes
9000A and 9000 H-Series (with software version 4.20 or higher)
a Infiniium 90000A and 90000 X/Q-Series oscilloscopes are not compatible
with N2820/1A current probes.
N2820/1A User’s Guide 77
Page 78
5 Characteristics and Specifications
NOTE
Current Range Graphs
Current Range Graphs
The following graphs show the minimum and maximum current
ranges versus R
These graphs represent a condition where the sensor leads are solder
attached to the R
of 500 mW is observed, and the oscilloscope is set to high-resolution.
resistance.
SENSE
resistor, the maximum probe-head power rating
SENSE
Figure 35 Current Range of N2822/4A Heads
78 N2820/1A User’s Guide
Page 79
Characteristics and Specifications 5
Current Range Graphs
Figure 36 Current Range of N2825A User-Defined Head
N2820/1A User’s Guide 79
Page 80
5 Characteristics and Specifications
NOTE
Zoomed-In Input Voltage Range Versus Supply Voltage
Zoomed-In Input Voltage Range Versus Supply Voltage
For the zoomed-in probe input, the following graph shows the
typical input voltage range allowed based on the supply voltage
that you are measuring. For example, when measuring a 5V input,
the input voltage range is ∴45 mV.
Figure 37 Zoomed-In Input Voltage Range Versus Supply Voltage
This plot can be used with N2825A heads (user-defined R
current range versus supply voltage.
80 N2820/1A User’s Guide
SENSE
) to verify
Page 81
Characteristics and Specifications 5
Zoomed-In Input Current Range Versus Supply Voltage
Zoomed-In Input Current Range Versus Supply Voltage
For the zoomed-in probe input, the following two graphs show the
typical input current range allowed based on the supply voltage
that you are measuring. For example, when using an N2824A head
and measuring a 5V input, the current range is ∴0.54A. When
using an N2822A head and measuring a 5V input, the current
range is ∴1.0A.
Figure 38 Zoomed-In Input Current Range Versus Supply Voltage
(N2824A 100 mΩ Head)
N2820/1A User’s Guide 81
Page 82
5 Characteristics and Specifications
Zoomed-In Input Current Range Versus Supply Voltage
Figure 39 Zoomed-In Input Current Range Versus Supply Voltage
(N2822A 20 mΩ Head)
82 N2820/1A User’s Guide
Page 83
Dimensions
Characteristics and Specifications 5
Dimensions
Figure 40 Probe and Tip Dimensions
N2820/1A User’s Guide 83
Page 84
5 Characteristics and Specifications
Dimensions
84 N2820/1A User’s Guide
Page 85
Keysight N2820/1A High-Sensitivity Current Probes
User’s Guide
6 Performance Data Plots
N2820A Frequency Response / 86
N2820A Common Mode Rejection Ratio / 88
N2820A Step Response / 89
N2820A Step Tracking / 90
N2820A Input Impedance / 92
Input Load Model / 93
This chapter provides the performance plots for the N2820A.
Page 86
6Performance Data Plots
N2820A Frequency Response
N2820A Frequency Response
BW: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 590 kHz
Figure 41 Frequency Response, Zoomed-In Channel
86 N2820/1A User’s Guide
Page 87
Performance Data Plots 6
N2820A Frequency Response
BW: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 MHz
Figure 42 Frequency Response, Zoomed-Out Channel
N2820/1A User’s Guide 87
Page 88
6Performance Data Plots
N2820A Common Mode Rejection Ratio
N2820A Common Mode Rejection Ratio
Figure 43 Common Mode Rejection Ratio (CMRR)
88 N2820/1A User’s Guide
Page 89
N2820A Step Response
Performance Data Plots 6
N2820A Step Response
Zoomed-In Channel
10–90% rising edge step: . . . . . . . . . . . . . . . . . . . . . . 584.2 ns
20–80% rising edge step: . . . . . . . . . . . . . . . . . . . . . . 365.8 ns
Zoomed-Out Channel
10–90% rising edge step: . . . . . . . . . . . . . . . . . . . . . . 96.76 ns
20–80% rising edge step: . . . . . . . . . . . . . . . . . . . . . . 63.33 ns
Figure 44 Step Response
N2820/1A User’s Guide 89
Page 90
6Performance Data Plots
N2820A Step Tracking
N2820A Step Tracking
Input Step
10–90% Rise Time: . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.688 µs
20–80% Rise Time: . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.153 µs
Output Step
10–90% Rise Time: . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.769 µs
20–80% Rise Time: . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.204 µs
Figure 45 Zoomed-In Channel Step Tracking
90 N2820/1A User’s Guide
Page 91
Performance Data Plots 6
N2820A Step Tracking
Input Step
10–90% Rise Time: . . . . . . . . . . . . . . . . . . . . . . . . . . . 446.9 ns
20–80% Rise Time: . . . . . . . . . . . . . . . . . . . . . . . . . . . 299.8 ns
Output Step
10–90% Rise Time: . . . . . . . . . . . . . . . . . . . . . . . . . . . 450.0 ns
20–80% Rise Time: . . . . . . . . . . . . . . . . . . . . . . . . . . . 302.6 ns
Figure 46 Zoomed-Out Channel Step Tracking
N2820/1A User’s Guide 91
Page 92
6Performance Data Plots
N2820A Input Impedance
N2820A Input Impedance
Figure 47 Input Impedance
92 N2820/1A User’s Guide
Page 93
Input Load Model
Performance Data Plots 6
Input Load Model
Z
Single Ended: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 GΩ
in
Zin Differential:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 GΩ
Figure 48 Input Load Model
N2820/1A User’s Guide 93
Page 94
6Performance Data Plots
Input Load Model
94 N2820/1A User’s Guide
Page 95
Keysight N2820/1A High-Sensitivity Current Probes
NOTE
NOTE
NOTE
CAUTION
User’s Guide
7 Performance Verification
Average Gain of Zoomed-In Channel / 97
Average Gain of Zoomed-Out Channel / 101
Performance Test Record / 105
This chapter describes how to verify the performance of the N2820A and N2821A
probes. The performance verification requires an N2825A probe head and consists
of verifying the probe’s DC gain.
The Average Gain verified in this chapter is listed as Gain in Table 10, “Characteristics and
Specifications,” on page 75.
The performance measured in this procedure is for the probe by itself. Keysight high
performance real-time scopes apply probe correction that will further enhance the
performance of the probes.
Keysight recommends a test interval of one year or 2000 hours of operation.
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 and insure that cables are discharged before being connected.
Page 96
7 Performance Verification
Table 13 Required Test Equipment
Test Equipment Recommended Model
Digital Multimeter General purpose instrument for DC voltage measurement.
DC Power Supply Recommended: ±20V
Probe Power Supply Keysight 1143A Probe Offset Control and Power Module
Probe Adapter Keysight N1022A/B Probe Adapter.
Adapters 3.5 mm-to-BNC
Maximum: ≤ ±35V
BNC-to-banana
96 N2820/1A User’s Guide
Page 97
Average Gain of Zoomed-In Channel
NOTE
NOTE
This procedure applies to both N2820A and N2821A probes.
Allow the probe to warm up for at least 20 minutes.
1 Snap an N2825A head onto the N2820/1A probe and connect the
test equipment as shown in Figure 49. Be sure to connect the
positive side of the DC supply to the red lead on the N2825A head.
Performance Verification 7
Average Gain of Zoomed-In Channel
Figure 49 Test Setup for Measuring V
2 Set the DC power supply to +20 mV.
Although this is the recommended setting, you can use any voltages up
to +35 mV.
N2820/1A User’s Guide 97
in
Page 98
7 Performance Verification
Average Gain of Zoomed-In Channel
3 Record the value of +V
measured on the multimeter:
in
+V
: ________________
in
4 Move the multimeter’s leads to the banana plug on the output of
the N1022A/B as shown in Figure 50.
5 Record the value of +V
measured on the multimeter:
out
+V
:________________
out
Figure 50 Test Setup for Measuring V
out
6 Calculate the positive gain of the zoomed-in (primary) channel and
record the result in the following line:
98 N2820/1A User’s Guide
Page 99
Performance Verification 7
positive gain
+V
out
+V
in
------------
=
NOTE
negative gain
–V
out
–V
in
------------
=
Average Gain of Zoomed-In Channel
positive gain: ________________
7 Set the DC power supply to –20 mV.
Although this is the recommended setting, you can use any negative
voltage less than –35 mV.
8 Connect the multimeter on the DC power supply as shown in
Figure 49 on page 97.
9 Record the value of –V
10 Connect the multimeter’s leads to the banana plug on the output
of the N1022A/B as shown in Figure 50 on page 98.
11 Record the value of –V
12 Calculate the negative gain of the zoomed-in (primary) channel
and record the result in the following line:
13 Calculate the average of the two gains:
measured on the multimeter:
in
–V
:________________
in
measured on the multimeter:
out
–V
:________________
out
negative gain:________________
N2820/1A User’s Guide 99
Page 100
7 Performance Verification
average gain
positive gain negative gain+
2
------------------------- ----------------------------- ---------
=
Average Gain of Zoomed-In Channel
average gain (zoomed-in):________________
14 The average gain (zoomed-in) should be 300 ±3%. Enter the value
in Table 14 on page 105.
100 N2820/1A User’s Guide
Loading...