Tektronix P6248 User manual

Instructions
P6248
1.7 GHz (Typical)
Differential Probe
071-0566-03

Copyright ©Tektronix, Inc. All rights reserved.
Tektronix products are covered by U.S. and foreign patents, issued and
pending. Information in this publication supercedes that in all previously
published material. Specifications and price change privileges reserved.
Tektronix, Inc., P.O. Box 500, Beaverton, OR 97077
TEKTRONIX, TEK, and TEKPROBE are registered trademarks of
Tektronix, Inc.
KlipChip, TwinFoot, TwinTip, and VariTip are trademarks of Tektronix, Inc.

WARRANTY
Tektronix warrants that the products that it manufactures and sells will be free from defects
in materials and workmanship for a period of one (1) year from the date of shipment. If a
product proves defective during this warranty period, Tektronix, at its option, either will
repair the defective product without charge for parts and labor, or will provide a
replacement in exchange for the defective product.
In order to obtain service under this warranty, Customer must notify Tektronix of the defect
before the expiration of the warranty period and make suitable arrangements for the
performance of service. Customer shall be responsible for packaging and shipping the
defective product to the service center designated by Tektronix, with shipping charges
prepaid. Tektronix shall pay for the return of the product to Customer if the shipment is to
a location within the country in which the Tektronix service center is located. Customer
shall be responsible for paying all shipping charges, duties, taxes, and any other charges for
products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or
improper or inadequate maintenance and care. Tektronix shall not be obligated to furnish
service under this warranty a) to repair damage resulting from attempts by personnel other
than Tektronix representatives to install, repair or service the product; b) to repair damage
resulting from improper use or connection to incompatible equipment; c) to repair any
damage or malfunction caused by the use of non-Tektronix supplies; or d) to service a
product that has been modified or integrated with other products when the effect of such
modification or integration increases the time or difficulty of servicing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX IN LIEU OF ANY OTHER
WARRANTIES, EXPRESS OR IMPLIED. TEKTRONIX AND ITS VENDORS
DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE. TEKTRONIX’ RESPONSIBILITY
TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND
EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF
THIS WARRANTY. TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE
FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR
HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.

P6248 1.7 GHz Differential Probe Instructions i
Table of Contents
General Safety Summary iii............................
Preface v............................................
Contacting Tektronix vi.................................
Getting Started 1.....................................
Features and Accessories 1..............................
Installation 8.........................................
Instruments with the TEKPROBE Interface (Tektronix TDS 400,
500, 600, and 700 Series Oscilloscopes) 9...............
Instruments without the TEKPROBE Interface 9............
Operating Basics 11...................................
Input Voltage Limits 11.................................
Maximum Input Voltage 11..............................
Common-Mode Signal Range 11..........................
Differential-Mode Signal Range 12........................
Attenuation Settings 12.................................
Probe Grounding 12....................................
Input Impedance and Probe Loading 14.....................
Common-Mode Rejection 15.............................
Probing Techniques to Maximize CMRR 15.................
Reference 17.........................................
Problems with Single-Ended Measurements 17...............
Differential Measurements 17............................
Common-Mode Rejection Ratio 18........................
Assessing CMRR Error 18...............................
Input Impedance Effects on CMRR 19.....................
Extending the Input Leads 19.............................
Extending the Ground Lead 20............................
Extending the Probe Output 20...........................
Terminating the Probe 20................................
Effect of Extending the Output Cable 21....................
Using the Probe with Other Instruments 21..................
Specifications 23......................................
Warranted Characteristics 23.............................
Typical Characteristics 25...............................
Nominal Characteristics 28..............................

Table of Contents
ii P6248 1.7 GHz Differential Probe Instructions
List of Figures
Figure 1: Input connector of TEKPROBE interface 8......
Figure 2: Using the short ground contact 13...............
Figure 3: Typical probe input model 14...................
Figure 4: Using the input lead accessories to achieve
high CMRR 15.....................................
Figure 5: Using the TwinFoot adapter 16..................
Figure 6: Simplified model of a differential amplifier 18.....
Figure 7: Twisting the Input Leads 20....................
Figure 8: Typical Common-Mode Rejection Ratio
(B1 and B10 attenuation) 26..........................
Figure 9: Typical differential input impedance versus
frequency 26.......................................
Figure 10: Probe head and compensation box dimensions 27.

P6248 1.7 GHz Differential Probe Instructions iii
General Safety Summary
Review the following safety precautions to avoid injury and prevent
damage to this product or any products connected to it. To avoid
potential hazards, use this product only as specified.
Only qualified personnel should perform service procedures.
To Avoid Fire or Personal Injury
Connect and Disconnect Properly. Connect the probe output to the
measurement instrument before connecting the probe to the circuit
under test. Disconnect the probe input and the probe ground from the
circuit under test before disconnecting the probe from the measure-
ment instrument.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all
ratings and markings on the product. Consult the product manual for
further ratings information before making connections to the product.
Connect the ground lead of the probe to earth ground only.
Do Not Operate Without Covers. Do not operate this product with
covers or panels removed.
Do Not Operate With Suspected Failures. If you suspect there is damage
to this product, have it inspected by qualified service personnel.
Do Not Operate in Wet/Damp Conditions.
Do Not Operate in an Explosive Atmosphere.
Keep Product Surfaces Clean and Dry.
Safety Terms and Symbols
Terms in This Manual. These terms may appear in this manual:
WARNING. Warning statements identify conditions or practices that
could result in injury or loss of life.

General Safety Summary
iv P6248 1.7 GHz Differential Probe Instructions
CAUTION. Caution statements identify conditions or practices that
could result in damage to this product or other property.
Terms on the Product. These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you
read the marking.
WARNING indicates an injury hazard not immediately accessible as
you read the marking.
CAUTION indicates a hazard to property including the product.
Symbols on the Product. These symbols may appear on the product:
CAUTION
Refer to Manual
Protective Ground
(Earth) Terminal

P6248 1.7 GHz Differential Probe Instructions v
Preface
This manual contains instructions and specifications for using the
P6248 differential probe.
Related Manuals
For performance verification procedures, adjustment procedures, a
list of replaceable parts, and other service information, refer to the
P6248 Service Manual (071-0573-XX).

Preface
vi P6248 1.7 GHz Differential Probe Instructions
Contacting Tektronix
Phone [phone]*
Address Tektronix, Inc.
Department or name (if known)
14200 SW Karl Braun Drive
P.O. Box 500
Beaverton, OR 97077
USA
Web site www.tektronix.com
Sales
support
1-800-833-9200, select option 1*
Service
support
1-800-833-9200, select option 2*
Technical
support
Email: [e-mail]
1-800-833-9200, select option 3*
6:00 a.m. -- 5:00 p.m. Pacific time
*This phone number is toll free in North America. After office
hours, please leave a voice mail message.
Outside North America, contact a Tektronix sales office or
distributor; see the Tektronix web site for a list of offices.

P6248 1.7 GHz Differential Probe Instructions 1
Getting Started
The P6248 is a high-bandwidth differential probe with the TEK-
PROBE interface. The P6248 probe has a bandwidth of 1.5 GHz
(1.7 GHz typical). The probe has low circuit loading, high common-
mode rejection, and comes with accessories that accommodate a
wide variety of applications.
The TEKPROBE interface is standard on Tektronix TDS series
oscilloscopes. The Tektronix 1103 TEKPROBE Power Supply can be
used for instruments without the TEKPROBE interface (refer to
page 7).
Features and Accessories
Table 1 shows the features and standard accessories of the P6248
differential probe.
Table 1: P6248 features and standard accessories
Feature/Accessory Description
TEKPROBE interface. The TEKPROBE interface supplies
power to the probe, selects the correct display scaling, and
automatically sets the 50 Ωtermination on the oscilloscope input.
If your oscilloscope does not have the TEKPROBE interface, you
can use the optional 1103 power supply (refer to page 7).
Probe attenuation. The attenuation switch selects either divide
by 1 (÷1) or divide by 10 (÷10).

Getting Started
2P6248 1.7 GHz Differential Probe Instructions
Table 1: P6248 features and standard accessories (Cont.)
Feature/Accessory Description
Ground
+
--
Input connections. The (+), (--), and ground connections of the
probe head accept the standard and optional probe accessories.
You can also plug the head directly onto a pair of 0.025-inch
square pins that have the standard spacing of 0.100-inch on
center.
CAUTION: To avoid damaging the input connectors, do not insert
anything larger than a 0.025-inch square pin into the inputs. To
prolong the life of the connectors, use the tip saver or smooth,
gold-plated pins only.
Instrument case. The instrument case protects the probe from
harsh environments and provides room for storing optional
accessories.
Replacement part number (P6248): 016-1879-XX
Calibration certificate. A certificate of traceable calibration is
provided with every instrument shipped.
Instructions. Provides instructions for operating the P6248
differential probe.
Replacement part number: 071-0566-XX

Getting Started
P6248 1.7 GHz Differential Probe Instructions 3
Table 1: P6248 features and standard accessories (Cont.)
Feature/Accessory Description
Service manual. Provides procedures for verifying the
performance, adjusting, and maintaining the P6248 differential
probe.
Replacement part number: 071-0573-XX
Probe tip accessory kit. This kit contains the accessories listed
below, in a plastic case. For more information on the individual
accessories, refer to Table 2 on page 4.
10 Color marker bands
2 Y-lead adapters
4 Short ground leads
2 Long ground leads
10 Short ground contacts
6 Spring-loaded ground pin
4 TwinTip adapters
5 Longhorn via adapters
8 Straight tip adapters
8 VariTip adapters
4 TwinFoot adapters
2 Tip savers
4 SMT KlipChip adapters
1 Probe-tip-to-BNC-adapter
Replacement part number: 020-2328-XX

Getting Started
4P6248 1.7 GHz Differential Probe Instructions
Table 2 describes the contents of the probe tip accessory kit.
Table 2: P6248 Probe tip accessory kit contents
Accessory Description
Color marker bands Color marker bands.Attach matching pairs of the color marker
bands onto the cable at the head and compensation box of each
probe. The marker bands enable quick verification of which probe
is connected to which instrument channel.
Replacement part number: 016-1315-00 (package of 10)
Lead set accessory kit. Includes (2) Y-lead adapters,
(4) three-inch ground leads and (2) six-inch ground leads
Replacement part number: 196-3462-00
Y-lead adapter. The Y-lead adapter plugs directly into the probe.
The socketed ends of the leads may be connected to the probe
tips and accessories, or fitted onto 0.025-inch pins.
Ground leads. Use the ground leads for connecting the probe
ground to the circuit. The socketed end of the lead may be
connected to the probe tips and accessories, or fitted onto
0.025-inch pins.
Short ground contact. Use the short ground lead for probing
small geometry components that have a nearby ground point. The
ground easily connects to adjacent square pins when the probe is
plugged directly onto 0.025-inch square pins (0.100-inch spacing).
See Figure 2 on page 13.
Replacement part number: 016-1783-00 (package of 10)
Spring-loaded ground pin. Use the spring-loaded ground when
probing components that have a nearby ground point.
Replacement part number: 016-1782-00 (package of 6)

Getting Started
P6248 1.7 GHz Differential Probe Instructions 5
Table 2: P6248 Probe tip accessory kit contents (Cont.)
Accessory Description
TwinTip adapter. This accessory provides two adjustable tips for
probing connections that are close to each other.
Replacement part number: 016-1786-00 (package of 4)
Longhorn via adapter. This accessory is similar to the TwinTip
adapter, but it has finer pins for probing smaller holes. Use this
accessory for probing circuit board through-holes (vias).
Replacement part number: 016-1780-00 (package of 5)
Straight tip adapter. The straight tip adapters plug directly into
the probe and allow you to take measurements from two points
spaced 0.100 inches apart. Use the straight tip adapters when
you need to measure fast waveforms that may be affected by the
longer length of other adapters.
Replacement part number: 016-1891-00 (package of 8)
VariTip adapter. The VariTip adapters plug into the probe and
allow you to measure two test points spaced between 0.020 and
0.180 inches apart. Use tweezers to adjust the spacing between
the pins.
Use the VariTip adapters to probe waveforms that have fast rise
times. The short length of the VariTip adapters minimize the
effects of increased probe tip inductance and capacitance on your
measurements.
Replacement part number: 016-1890-00 (package of 8)
TwinFoot adapter. Use the TwinFoot adapter to probe two
adjacent leads on a surface-mount integrated circuit. Flexible
fingers adapt to a range of lead spacings. See Figure 5 on
page 16.
Replacement part number: 016-1785-00 (package of 4)

Getting Started
6P6248 1.7 GHz Differential Probe Instructions
Table 2: P6248 Probe tip accessory kit contents (Cont.)
Accessory Description
Tip saver. Use the tip saver to prolong the life of your probe tip
contacts. The tip saver connects to the probe and accepts the
probe tip accessories, bearing the wear of repeated connections
of different probe tips.
Replacement part number: 016-1781-00 (package of 2)
SMT KlipChip adapters. Use this accessory to probe the leads
on dual-in-line packages (DIP).
Replacement part number: 206-0364-XX
Probe-tip-to-BNC adapter. This accessory adapts the probe to a
BNC connector.
Replacement part number: 679-4094-00

Getting Started
P6248 1.7 GHz Differential Probe Instructions 7
Table 3 shows the optional accessories that you can order for the
P6248 differential probe.
Table 3: Optional accessories and instrument options
Accessory/Option Description
1103 Power supply. Order the 1103 power supply for instruments
that do not have the TEKPROBE Interface. Power cord options
are available for the following countries or regions.
Standard. North America and Japan
Option A1. European
Option A2. UK
Option A3. Australia
Option A5. Switzerland
50 Ωtermination. Terminates the output of the 1103 power
supply to the required 50 Ωif the oscilloscope does not have a
50 Ωinput setting. Order 011-0049-01.
50 ΩBNC cable. Connects to the 1103 output.
Replacement part number: 012-0076-00
IEEE1394 Adapter. The IEEE1394 Adapter allows you to probe
signals on the bus, external to system enclosures, without
disturbing system operation. The adapter maintains a balanced
55 Ωsignal path and can be used in both single-ended and
differential modes.
Replacement part number: 679-5027-00
Micro KlipChip adapters. Use the adapters to probe the leads
on integrated circuits that are surface-mounted.
Replacement part number: SMK4 (package of 4)

Getting Started
8P6248 1.7 GHz Differential Probe Instructions
Table 3: Optional accessories and instrument options (Cont.)
Accessory/Option Description
Adjustment tool. Use for making internal adjustments to the
probe. Order 003-0675-01.
Calibration data (Option 95). Option 95, which must be ordered
at the time of purchase, documents the measurements taken
during calibration.
Installation
Before you connect the output of the P6248 differential probe,
determine whether or not your oscilloscope has a TEKPROBE
interface. See Figure 1.
Figure 1: Input connector of TEKPROBE interface

Getting Started
P6248 1.7 GHz Differential Probe Instructions 9
Instruments with the TEKPROBE Interface (Tektronix TDS 400, 500, 600,
and 700 Series Oscilloscopes)
On instruments that have the TEKPROBE interface, simply connect
the probe to the input. The TEKPROBE interface provides power,
selects the correct display scaling, and automatically sets the 50 Ω
termination on the oscilloscope input.
NOTE. TDS 400 and TDS 400A series oscilloscopes do not interpret
the scale factor coding of the P6248 differential probe. This problem
is only apparent when the probe is in the ÷1 position. To correct for
this problem, divide the measurement (or scale factor) by 10 when
you use the probe in the ÷1 position.
Instruments without the TEKPROBE Interface
On instruments that do not have the TEKPROBE interface, you must
order the optional 1103 power supply (refer to page 7). Each 1103
can supply power for two probes. The input of the oscilloscope must
also terminate into 50 Ω. Refer to page 20 for information on the
effects of extending the output of the probe.
When you set the attenuation of the probe, you must factor that
attenuation into your measurement. For example, if the probe is set
at ÷10 and the instrument displays a 0.2 Vp--p signal, the actual
amplitude of the signal is 2 Vp--p.

Getting Started
10 P6248 1.7 GHz Differential Probe Instructions