User’s
Guide
HP N1020A—at a glance 2
Installing the Probe 4
Normalizing the Probe 6
Probe Characteristics 10
Replaceable Parts 11
Contacting HP 12
Warranty 13
Safety Symbols 14
HP N1020A TDR Probe
HP N1020A—at a glance
The HP N1020A TDR Probe facilitates accurate, repeatable time domain reflectometry measurements in situations where RF connectors are unavailable. It is ideal for
use with the HP 54753A and HP 54754A TDR plug-in
modules.
Figure 1. HP N1020A TDR Probe
The HP N1020A TDR Probe includes the following
items:
■ RF cable (SMA, 36-inch)
■ Calibration substrate (quantity 2)
■ Grounding pin
■ Tweezer
2
Figure 2. Probe tip and grounding pin
Accessories available
The following accessories are available from Cascade
Microtech®.
Internet address: http://www.cascademicrotech.com
■ Fixed-pitch compliant 50
hybrids, and MCMs. Bandwidth from dc to 20 GHz.
Order FPC-GSG-xxxx probe.
■ Fine-pitch active 100k
brids, and MCMs. Bandwidth from dc to 2.5 GHz. Order FPA-10X probe.
■ DC coaxial microprobes
■ Fine-pitch microprobes
■ Fine-pitch DC needle holder
Ω
probe for testing SMTs,
Ω
probe for testing SMTs, hy-
3
Installing the Probe
Locate the
1
grounding pin
supplied with
the probe.
As explained in
2
the following
caution
statement,
insert the long
end of the
grounding pin
into one of the holes that are located in the tip of the
probe. Select any hole that is located in the spiral
pattern.
CAUTION
connected by a spring. To avoid damaging the grounding pin,
always insert the longest solid end into the probe tip.
Using tweezers, gently push the pin until it is fully
3
seated into the hole.
Connect the supplied SMA cable to the TDR probe.
4
CAUTION
can be damaged by electrostatic discharge.
Discharge any static buildup on the SMA cable.
5
Momentarily short the center and outer conductors
of the cable together. Avoid touching the front-panel
input connectors without first touching the frame of
the instrument.
4
The grounding pin consists of two solid end pieces
The input circuits on the HP 83480A plug-in modules
6 Connect the other end of the SMA cable to the TDR
plug-in module’s Channel input connector.
Moving the grounding pin
The probe comes with a movable grounding pin to make
connections to the ground plane easier. Use the following steps to move of grounding pin:
1 Using the supplied tweezers, gently pull the pin out
of the probe tip.
2 Insert the pin into one of the adjacent, conveniently-
located holes. Notice that these holes are in a spiral
pattern.
3 Using the tweezers, gently push the pin until it is
fully seated into the hole.
5
Normalizing the Probe
Normalizing the probe ensures accurate measurements
with HP 54753A and HP 54754A TDR plug-in modules.
To learn more about normalization, refer to the
HP 83480A User’s Guide and the HP 54753A and
HP 54754A User’s Guide. For the most recent version
of these books, visit the following Internet web site http:/
/www.hp.com/go/lightwave, and “click” on Support.
The TDR probe comes with two identical calibration
substrates. During the normalization procedure, the calibration substrate is used to move the measurement
plane from the module’s input connector to the end of
the probe tip. Each calibration substrate provides one
Ω
short pad, three 28
Ω
75
pads for probing. Three pads of each type are provided in the event that pads becomes damaged or worn
out with use.
When probing, always connect the probe’s ground to
the larger side of the resistant pad.
pads, three 50Ω pads, and three
Figure 3. Calibration substrate
6
Ω
The 28
and 75Ω pads are provided so that you can
verify measurement normalization on devices that have
a characteristic impedance other than 50Ω. For example, Rambus®
*
technology has a 28Ω characteristic
impedance. Regardless of the characteristic impedance
Ω
of the device being measured, always use the 50
ter-
mination pad during the normalization procedure.
CAUTION
Do not touch the 75Ω, 50Ω, or 28Ω pads. These
pads are precision resistors. Their values can be altered by
contamination (such as oils and dirt) or electrostatic discharge.
To normalize the probe
1 Press the Setup key and then Default setup on the
HP 83480A mainframe.
2 Remove any connections from the HP 54753A or
HP 54754A front-panel channel input connectors.
3 Press Utility, Calibrate, and then Calibrate plug-in.
4 Select the plug-in module to be calibrated, press 1
and 2 or 3 and 4.
5 Press Start cal to start the calibration, and follow the
on-screen instructions. This step completes a plugin module vertical calibration.
CAUTION
The input circuits on the HP 83480A plug-in modules
can be damaged by electrostatic discharge.
6 Discharge any static buildup on the TDR probe’s
SMA cable. Momentarily short the center and outer
conductors of the cable together. Avoid touching the
front-panel input connectors without first touching
*. Rambus® is a trademark of Rambus Inc.
7
the frame of the instrument.
7 Connect the SMA cable on the probe to the TDR
plug-in module’s Channel input connector.
8 Press Setup on the TDR plug-in module. Press
Stimulus and select 1 only. Press Enter and then Preset
TDR/TDT.
9 Connect the TDR probe to the device that you are
testing.
10 Use the HP 83480A’s Time base key to adjust the time
scale and position so that the desired response is
displayed. Changing the time base setting after the
calibration voids the calibration.
The following two steps perform a normalization routine. These steps move the measurement plane from
the module’s input connector to the end of the probe
tip.
11 Press Setup on the plug-in module. Press Normalize
response and then Establish normalization & ref plane.
12 Follow the onscreen instructions (upper left-hand
corner). Use the short and 50
calibration substrate for short and 50
terminations.
Ω
pads on the
Ω
NOTE
and 50
procedure, you can use the 28
ment accuracy for devices having a characteristic impedance of
28Ω or 75Ω.
The following two steps activate the normalized
response.
8
During the normalization procedure, use only the short
Ω
termination pads on the calibration substrate. After the
Ω
pad or 75Ω pad to verify measure-
13 Press Setup on the TDR plug-in module.
14 Press Normalize Response and then set TDR normalize to
on.
15 Press Channel 1/3 and then set Display to off. This step
is optional.
16 On the HP 83480A mainframe, press Marker. Set Mode
to TDR/TDT.
17 Set
+
Source to response 1 and then press Enter.
18 Set Reference so that ref plane is selected.
19 Press
20 Press
21 Set × Source to response 1 and then press Enter.
Use the following optional steps to simulate the impedance profile of the device that you are testing as a function of the incident TDR step rise time.
22 Press Setup on the TDR plug-in module.
23 Press Normalize response and then Risetime.
24 Enter the desired rise time, and then press Enter.
Setting the rise time value too fast results in a noisy
normalized waveform. This is because the bandwidth of
the system has been exceeded. Increase the rise time
until the noise on the normalized waveform disappears.
+
Position, the 0 key, and then the Enter key that
is located next to the numeric keypad.
×
Position, the 0 key, and then the Enter key that
is located next to the numeric keypad.
+
and × markers should now be visible on the
The
displayed normalized response.
9
Probe Characteristics
There are no specifications for HP N1020A TDR Probe.
(Product specifications describe warranted performance.) However, the following characteristics provide
useful information by giving functional, but nonwarranted, performance parameters.
Table 1. Characteristics of TDR Probe
Description Characteristic
Bandwidth DC to 6 GHz
.Insertion loss < 1.5 dB
Return loss > 16 dB
Connector 3.5 mm SMA
Weight 1.3 kg
Joystick travel 17 x 17 x 13 mm
Arm reach 100 to 220 mm
Arm sweep angle
Probe pitch 1.5 to 5.0 mm
10
+90
°
Replaceable Parts
The following table lists the replaceable parts for the
probe. Notice that the grounding pin must be ordered
from Inter-Continental Microwave Company:
Phone: . . . . . . . . . . . . . . . . . . . . . . . . . . . (408) 727-1596
Fax number: . . . . . . . . . . . . . . . . . . . . . . (408) 727-0105
Internet address: . . . . . . . . . . http://www.icmicrowave.com
Email address: . . . . . . . . . . . . . . . . . . ICMfixture@aol.com
Table 2. Replaceable Parts and Accessories
Description Part Number
Grounding pin
SMA cable (m) 36” (91.4 cm) 8120-4977
Calibration substrate 1NB7-8474
Tweezer 8710-1308
*. Order from Inter-Continental Microwave Co.
*
41112542
11
Contacting HP
To learn about other signal integrity test solutions, visit
our Internet web site at the following address:
http://www.hp.com/go/tdr
Before returning the probe for service, call the HP
Instrument Support Center at (800) 403-0801. Always
call the HP Instrument Support Center first to initiate
service before returning your probe to a service office.
This ensures that the repair can be properly tracked
and that your probe will be returned to you as quickly
as possible. Call this number regardless of where you
are located.
If the instrument is still under warranty or is covered by
an HP maintenance contract, it will be repaired under
the terms of the warranty or contract. If the instrument
is no longer under warranty or is not covered by an HP
maintenance plan, Hewlett-Packard will notify you of
the cost of the repair after examining the unit. When an
instrument is returned to a Hewlett-Packard service
office for servicing, it must be adequately packaged and
have a complete description of the failure.
12
Warranty
This Hewlett-Packard instrument product is warranted
against defects in material and workmanship for a
period of one year from date of shipment. During the
warranty period, Hewlett-Packard Company will, at its
option, either repair or replace products which prove to
be defective. For warranty service or repair, this product must be returned to a service facility designated by
Hewlett-Packard. Buyer shall prepay shipping charges
to Hewlett-Packard and Hewlett-Packard shall pay shipping charges to return the product to Buyer. However,
Buyer shall pay all shipping charges, duties, and taxes
for products returned to Hewlett-Packard from another
country.
Limitation of Warranty.
The foregoing warranty shall not apply to defects
resulting from improper or inadequate maintenance by
Buyer, Buyer-supplied software or interfacing, unauthorized modification or misuse, operation outside of the
environmental specifications for the product, or
improper site preparation or maintenance.
No other warranty is expressed or implied. HewlettPackard specifically disclaims the implied warranties of
merchantability and fitness for a particular purpose.
Exclusive Remedies.
The remedies provided herein are buyer's sole and
exclusive remedies. Hewlett-Packard shall not be liable
for any direct, indirect, special, incidental, or consequential damages, whether based on contract, tort, or
any other legal theory.
13
Safety Symbols
CAUTION
to a procedure which, if not correctly performed or adhered to,
could result in damage to or destruction of the product. Do not
proceed beyond a caution sign until the indicated conditions are
fully understood and met.
WARNING
The caution sign denotes a hazard. It calls attention
The
warning
attention to a procedure which, if not correctly
performed or adhered to, could result in injury
or loss of life. Do not proceed beyond a
warning sign until the indicated conditions are
fully understood and met.
sign denotes a hazard. It calls
14
© Copyright Hewlett-Packard Company 1999
All Rights Reserved. Reproduction, adaptation, or translation without prior written permission is prohibited,
except as allowed under copyright laws.
Hewlett-Packard Company
Lightwave Operations
1400 Fountaingrove Parkway
Santa Rosa, CA 95403-1799, USA
(707) 577-1400
Notice.
The information contained in this document is subject
to change without notice. Companies, names, and data
used in examples herein are fictitious unless otherwise
noted. Hewlett-Packard makes no warranty of any kind
with regard to this material, including but not limited
to, the implied warranties of merchantability and fitness
for a particular purpose. Hewlett-Packard shall not be
liable for errors contained herein or for incidental or
consequential damages in connection with the furnishing, performance, or use of this material.
Restricted Rights Legend.
Use, duplication, or disclosure by the U.S. Government
is subject to restrictions as set forth in subparagraph
(c) (1) (ii) of the Rights in Technical Data and Computer Software clause at DFARS 252.227-7013 for DOD
agencies, and subparagraphs (c) (1) and (c) (2) of the
Commercial Computer Software Restricted Rights
clause at FAR 52.227-19 for other agencies.
15
HP Part No. N1020-90001
Printed in USA
July 1999
16
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