Tektronix P6248 User manual

xx
P6248
1.7 GHz (Typical)
Differential Probe
ZZZ
Service Manual
*P071057304*
071-0573-04

P6248
1.7 GHz (Typical)
Differential Probe
ZZZ
Service Manual
xx
Warning
The servicing instructions are for use by qualified personnel
only. To avoid personal injury, do not perform any servicing
unless you are qualified to do so. Refer to all safety summaries
prior to performing service.
www.tektronix.com
071-0573-04

Copyright © Tektronix. All rights reserved. Licensed software products are owned by Tektronix or its subsidiaries
or suppliers, and are protected by national copyright laws and international treaty provisions.
Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication
supersedes that in all previously published material. Specifications and price change privileges reserved.
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
KlipChip, TwinFoot, TwinTip, and VariTip are trademarks of Tektronix, Inc.
Contacting Tektronix
Tektronix, Inc.
14200 SW Karl Braun Drive
P.O. Box 500
Beaverton, OR 97077
USA
For product information, sales, service, and technical support:
In North America, call 1-800-833-9200.
Worldwide, visit www.tektronix.com to find contacts in your area.

Warranty
Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one (1)
year from the date of shipment. If any such 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. Parts, modules and replacement products used by Tektronix for warranty
work may be new or reconditioned to like new performance. All replaced parts, modules and products become
the property of Tektronix.
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 WITH RESPECT TO THE PRODUCT 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.
[W2 – 15AUG04]

Table of Contents
General Safety Summary ......................................................................................... iii
Service Safety Summary........................................................................................... v
Preface............................................................................................................. vii
Related Manuals ............................................................................................. vii
Specifications ....................................................................................................... 1
Warranted Characteristics..................................................................................... 1
Typical Characteristics ........................................................................................ 2
Nominal Characteristics....................................................................................... 4
Performance Verification .......................................................................................... 5
Equipment Required........................................................................................... 5
Preparation...................................................................................................... 6
Output Offset Voltage ......................................................................................... 7
DC Attenuation Accuracy .................................................................................... 8
Differential Signal Range..................................................................................... 9
Rise Time...................................................................................................... 11
Common-Mode Rejection Ratio ............................................................................ 14
TEKPROBE Communication (Operational Check) ...................................................... 17
Adjustment Procedures ........................................................................................... 19
Equipment Required.......................................................................................... 19
Adjustment locations......................................................................................... 20
Offset (preliminary) .......................................................................................... 21
Gain ............................................................................................................ 22
Offset (Final).................................................................................................. 23
DC CMRR..................................................................................................... 24
AC CMRR..................................................................................................... 26
Maintenance........................................................................................................ 27
Cleaning ....................................................................................................... 27
Replacing TEKPROBE Interface Pins ..................................................................... 27
Removing and Replacing the TEKPROBE Interface Collar............................................. 28
Options.............................................................................................................. 29
Replaceable Parts.................................................................................................. 31
Appendix A: Alternate Verification Procedures................................................................ 37
Equipment Required.......................................................................................... 37
Preparation..................................................................................................... 38
CMRR (Common-Mode Rejection Ratio) ................................................................. 38
P6248 1.7 GHz Differential Probe Service Manual i

Table of Contents
List of Figures
Figure 1: Typical Common-Mode Rejection Ratio (÷1 and ÷10 attenuation) ............................... 3
Figure 2: Typical differential input impedance versus frequency............................................. 3
Figure 3: Dimensions of probe head and compensation box .................................................. 4
Figure 4: Setup for the output offset voltage test ............................................................... 7
Figure 5: Setup for differential-mode tests ...................................................................... 9
Figure 6: Test system rise time setup............................................................................ 11
Figure 7: Rise time setup for test system with probe.......................................................... 12
Figure 8: Setup for CMRR test .................................................................................. 15
Figure 9: Adjustment locations .................................................................................. 20
Figure 10: Setup for the offset adjustment...................................................................... 21
Figure 11: Setup for gain adjustment............................................................................ 22
Figure 12: Setup for DC CMRR and AC CMRR adjustments ............................................... 24
Figure 13: Replacing TEKPROBE interface pins ............................................................. 27
Figure 14: Replacing the TEKPROBE collar .................................................................. 28
Figure 15: P6248 replaceable parts.............................................................................. 31
Figure 16: P6248 standard accessories.......................................................................... 32
Figure 17: P6248 optional accessories.......................................................................... 34
Figure 18: Normalizing the setup................................................................................ 38
Figure 19: Setup for the CMRR tests ........................................................................... 39
ii P6248 1.7 GHz Differential Probe Service Manual

General Safety Summary
General SafetySummary
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. Do not connect or disconnect probes or test
leads while they are connected to a voltage source.
Ground the Product. This product is indirectly grounded through the grounding
conductor of the mainframe power cord. To avoid electric shock, the grounding
conductor must be connected to earth ground. Before making connections to
the input or output terminals of the product, ensure that the product is properly
grounded.
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 probe reference lead 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 that there is damage to this
product, have it inspected by qualified service personnel.
Avoid Exposed Circuitry. Do not touch exposed connections and components
when power is present.
Do Not Operate in Wet/Damp Conditions.
Do Not Operate in an Explosive Atmosphere.
Keep Product Surfaces Clean and Dry.
Provide Proper Ventilation. Refer to the manual’s installation instructions for
details on installing the product so it has proper ventilation.
P6248 1.7 GHz Differential Probe Service Manual iii

General Safety Summary
TermsinthisManual These terms may appear in this manual:
WARNING. Warning statements identify conditions or practices that could result
in injury or loss of life.
CAUTION. Caution statements identify conditions or practices that could result in
damage to this product or other property.
Symbols and Terms on the
Product
These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you read
the marking.
WARN IN G indicates an injury hazard not immediately accessible as you
read the marking.
CAUTION indicates a hazard to property including the product.
The following symbol(s) may appear on the product:
iv P6248 1.7 GHz Differential Probe Service Manual

Service Safety Summary
Service Safety Summary
Only qualified personnel should perform service procedures. Read this Service
Safety Summary and the General Safety Summary before performing any service
procedures.
Do Not Service Alone. Do not perform internal service or adjustments of this
product unless another person capable of rendering first aid and resuscitation is
present.
Disconnect Power. To avoid electric shock, switch off the instrument power, then
disconnect the power cord from the mains power.
UseCareWhenServicingWithPowerOn. Dangerousvoltagesorcurrentsmay
exist in this product. Disconnect power, remove battery (if applicable), and
disconnect test leads before removing protective panels, soldering, or replacing
components.
To avoid electric shock, do not touch exposed connections.
P6248 1.7 GHz Differential Probe Service Manual v

Service Safety Summary
vi P6248 1.7 GHz Differential Probe Service Manual

Preface
This manual contains specifications and service information for the
P6248 differential probe.
Related Manuals
For operating information, refer to the P6248 Instructions (071-0566-XX).
P6248 1.7 GHz Differential Probe Service Manual vii

Preface
viii P6248 1.7 GHz Differential Probe Service Manual

Specifications
The specifications in the following tables apply to a P6248 differential probe
installed on a Tektronix TDS694C oscilloscope. When the probe is used with
another oscilloscope, the oscilloscope must have an input impedance of 50 Ω.The
probe must have a warm-up period of at least 20 minutes and be in an environment
that does not exceed the limits described in the environmental specifications
table. Specifications for the P6248 differential probe fall into three categories:
warranted, typical, and nominal characteristics.
Warranted Characteristics
Warranted characteristics describe guaranteed performance within tolerance limits
or certain type-tested requirements. (See Table 1.) Warranted characteristics
that havechecksinthePerformance Verification section are marked with the
symbol.
Table 1: Warranted electrical characteristics
Characteristic Description
DC attenuation
accuracy
±2% for input voltages ±750 mV (÷1) and ±7.5 V (÷10)
±5% for input voltages ±850 mV (÷1) and ±8.5 V (÷10)
Maximum
nondestructive
input voltage
±25 V(DC + peak AC) between signal and common of the same channel
Differential signal
range (DC coupled)
±8.5 V at attenuation setting of ÷10
±850 mV at attenuation setting of ÷1
Common-mode signal
range (DC coupled)
±7 V
Output offset
voltage
±10mV(+20to+30ºC,+68to+86ºF)
±50 mV (0 to +50 ºC, +32 to +122 ºF)
Rise time (probe only) <265 ps
Common-mode
rejection ratio
45 dB at 1 MHz in ÷10
25 dB at 100 MHz in ÷10
20 dB at 500 MHz in ÷10
18 dB at 1 GHz in ÷10
60 dB at 1 MHz in ÷1
38 dB at 100 MHz in ÷1
35 dB at 500 MHz in ÷1
30 dB at 1 GHz in ÷1
Bandwidth (probe only) DC to ≥1.5 GHz (-3dB)
P6248 1.7 GHz Differential Probe Service Manual 1

Specifications
Table 1: Warranted electrical characteristics (cont.)
Characteristic Description
Temperature Operating: 0 to +50 ºC (+32 to +86 ºF),
0 to +60 ºC (+32 to +122 ºF) 1(probe head)
Nonoperating: -55 to +75 ºC (-131 to +167 ºF) 1
Humidity Operating: 0-90% RH, tested at +30 to +50 ºC (+68 to +122 ºF)
Nonoperating: 0-90% RH, tested at +30 to +60 ºC (+68 to +140 ºF)
1See warning that follows.
WARNING. To avoid a burn hazard at high ambient temperatures, do not touch
the probe with bare hands at operating temperatures above +50 °C (+122 °F)
or at nonoperating temperatures above +70 °C (+158 °F). Allow sufficient time
for the probe to cool before handling.
Typical Characteristics
Typical characteristics describe typical but not guaranteed performance. (See
Table 2.)
Table 2: Typical electrical characteristics
Characteristic Description
Differential input
resistance,
DC coupled
200 kΩ±2%
Common-mode input
resistance, DC coupled
100 kΩ±2%
Differential input
capacitance
<1 pF at 1 MHz
Common-mode input
capacitance
<2pFat1MHz
Harmonic distortion ≤1.5% measured using 354 mVRMS (or 1.0 VP-P) output at 100 MHz
Differential offset range ±700 mV (÷1 range), ±7 V (÷10 range)
Common mode
rejection ratio
(See Figure 1 on page 3.)
Random noise <50 nV/ √Hz @100 MHz
Input impedance (See Figure 2 on page 3.)
Pass band ripple ≤±0.5 dB to 850 MHz (deviation from a nominal slope)
Bandwidth (probe only) DC to ≥1.7 GHz (- 3dB) @ ≤27 ºC (÷1 range)
DC to ≥1.85 GHz (- 3dB) @ ≤27 ºC (÷10 range)
Rise time (probe and
oscilloscope)
<265 ps
2 P6248 1.7 GHz Differential Probe Service Manual

Specifications
Figure 1: Typical Common-Mode Rejection Ratio (÷1 and ÷10 attenuation)
Figure 2: Typical differential input impedance versus frequency
P6248 1.7 GHz Differential Probe Service Manual 3

Specifications
Table 3: Typical mechanical characteristics
Characteristic Description
Dimensions, input
connection
0.63 mm (0.025 in) square pin on 2.54 mm (0.100 in) centers
Dimensions, control
box
107 mm × 41 mm × 26 mm (4.2 in × 1.6 in × 1.0 in)
Dimensions, probe
head
78 mm × 12 mm × 9.3 mm (3.0 in × 0.47 in × 0.36 in)
Dimensions, output
cable
1.2m(47in)
Unit weight (probe only) 160 g (5.4 oz)
Figure 3: Dimensions of probe head and compensation box
Nominal Characteristics
Nominal characteristics describe guaranteed traits, but the traits do not have
tolerance limits. (See Table 4.)
Table 4: Nominal electrical characteristics
Characteristic Description
Input configuration Differential (two inputs, + and - ), with case ground
Output coupling DC
Attenuation settings ÷1 and ÷10
Termination Terminate output into 50 Ω
4 P6248 1.7 GHz Differential Probe Service Manual

Performance Verification
Use the following procedures to verify the warranted specifications of the P6248
Differential Probe. Before beginning these procedures, photocopy the test record
and use it to record the performance test results. The recommended calibration
interval is one year.
These procedures test the following specifications:
Output offset voltage
DC attenuation accuracy
Differential signal range
Rise time
Common mode rejection ratio
Equipment Required
The equipment required to perform the performance verification procedure is
listed below. (See Table 5.) The types and quantities of connectors may vary
depending on the specific equipment you use.
NOTE. If you cannot obtain a network analyzer, refer to the appendix for
procedures that do not require a network analyzer to perform the CMRR tests.
(See page 37, Alternate Verification Procedures.)
Table 5: Test equipment
Description Minimum requirements Example product 1
Calibrated DC voltage source
(2 required)
Adjustable from 0 V to ≥17 V. Outputs must be isolated
from earth ground. DC bench supplies monitored with
DMM are adequate.
Tektronix PS280
DMM
(2 required)
DC Accuracy ≥0.5% on range to measure 8.5 V,
averaging mode.
Tektronix DMM916
Network analyzer 100 kHz to ≥2 GHz, with cables and adapters to BNC male Hewlett-Packard 8753D
Digitizing oscilloscope
with TEKPROBE interface
Fully compatible with TEKPROBE interface (needed only
for functional check of the TEKPROBE interface)
Tektronix TDS500,
TDS600, or TDS700 series
oscilloscope
Oscilloscope with sampling head Tektronix 11800 series
oscilloscope with SD-24
TEKPROBE Power Supply Tektronix Type 1103 Tektronix Type 1103
BNC cables (2) 50 Ω,42inch 012-0057-01
SMA cables (2) 50 Ω015-0562-00
P6248 1.7 GHz Differential Probe Service Manual 5

Performance Verification
Table 5: Test equipment (cont.)
Description Minimum requirements Example product 1
Banana-to-banana patch cords (3) 2red
1black
012-0031-00
012-0039-00
Adapter (3) Dual-male-banana-to-female BNC 103-0090-00
Adapter (2) BNC male to dual binding post 103-0035-00
0.025" square pins (3) Approximately 0.75 inch long, smooth, gold plated. 131-1614-00
Precision in-line BNC termination 50 Ω±0.1% 011-0129-00
Probe ground lead (included in the standard probe tip accessory kit) 196-3437-XX
Adapter Y-lead (included in the standard probe tip accessory kit) 196-3434-XX
Adapter BNC-to-probe tip 679-4094-XX
Adapter SMA Male-to-male 015-1011-00
Adapter (2) SMA Female-to-BNC male 015-0572-00
1Nine-digit part numbers are Tektronix part numbers.
Preparation
Prepare the equipment as follows:
1. Connect the Y-lead adapter to the inputs of the probe and the ground lead to
the probe ground. (For a description of these accessories, refer to the list of
standard accessories.)
2. Attach the probe to the 1103 TEKPROBE power supply.
3. If necessary, set the line selector of the 1103 power supply to the correct
voltage.
4. Turn on the 1103 power supply.
5. Set the 1103 offset to off (button not illuminated).
6. Allow the probe and test equipment to warm up for 20 minutes at an ambient
temperatureof20ºCto30ºC(68ºFto86ºF).
Perform the verification procedures in order.
6 P6248 1.7 GHz Differential Probe Service Manual