Tektronix P7380SMA User manual

Instruction Manual
P7380SMA
8 GHz Differential Probe
071-1392-01
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

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 TekConnect are registered 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.

P7380SMA 8 GHz Differential Probe Instruction Manual i
Table of Contents
Preface vii............................................
Contacting Tektronix viii.................................
General Safety Summary ix..............................
Service Safety Summary xi..............................
Getting Started 1.....................................
Probe Controls and Connections 2........................
Standard Accessories 6.................................
Optional Accessories 8.................................
Options 10............................................
TekConnect Interface 11.................................
Probe Inputs 12........................................
SMA Connectors 12.................................
DC Termination Voltage Control Jacks 13................
Probe Input Limitations 13............................
Probe Outputs 14......................................
Termination Voltage Monitor Jacks 14...................
Auxiliary Output SMA Connector 14....................
Functional Check 15....................................
Power-on Self Test 16................................
Signal and Termination Voltage Monitor Check 17.........
Aux Output Check 20................................
DC Termination Voltage Zero Check 22.................
Probe Calibration 24....................................
Using the Probe 26.....................................
Auto Mode 26......................................
External Mode 27...................................
Internal Mode 28....................................
Auxiliary Output 29.................................
Using the Probe With a Sampling Oscilloscope 30.........
P6150 Probe Tips 32.................................
Operating Basics 33...................................
Differential Measurements for Serial Data Compliance Testing 33
Differential Signalling 33.............................
Pseudo-Differential Measurements 34...................
Differential Probe Measurements 35....................
Common-Mode Rejection Ratio 36.....................

Table of Contents
ii P7380SMA 8 GHz Differential Probe Instruction Manual
Probe Block Diagram (Simplified) 37......................
Matched-Delay Cables 37.............................
Input Termination Network 38.........................
Internal Probe Amplifier 40...........................
Termination Voltage Control 44...........................
Auto Mode 45......................................
Int Mode 45........................................
Ext Mode 45.......................................
Overdrive Error 47.....................................
Differential and Single-Ended Signal Measurement 48.........
Differential Measurement Topology 48..................
Differential Dynamic Range 49........................
Single-Ended Measurement Topology 50.................
Single-Ended Measurement Procedure 54................
Single-Ended Dynamic Range 55.......................
Extending the Input Connections 56.......................
Checking Cable Skew 57................................
Adjusting Cable Skew 58................................
Deskewing Probes 60...................................
Reference 63.........................................
Serial Bus Standards 63.................................
InfiniBand 64.........................................

Table of Contents
P7380SMA 8 GHz Differential Probe Instruction Manual iii
Appendix A: Specifications 65...........................
Warranted Characteristics 65.............................
Typical Characteristics 66...............................
Nominal Characteristics 71..............................
Mechanical Characteristics 71............................
Appendix B: Performance Verification 73.................
Equipment Required 73.................................
Special Adapters Required 75............................
TekConnect-to-SMA Adapter 75.......................
Equipment Setup 76....................................
Input Resistance 77.....................................
Termination Voltage Accuracy 78.........................
Ext Mode 78.......................................
Int Mode 79........................................
Auto Mode 80......................................
Output Offset Zero 82...................................
DC Gain Accuracy 83...................................
Gain Check at 2.5X Attenuation 83.....................
Gain Check at 12.5X Attenuation 85....................
Rise Time 85..........................................
Rise Time Check at 12.5X Attenuation 85................
Rise Time Check at 2.5X Attenuation 89.................
Appendix C: User Service 91............................
Probe/Adapter/Oscilloscope Compatibility 91................
Check Compatibility 91..............................
Error Conditions 92....................................
Inspection and Cleaning 93..............................
Replacement Parts 93...................................
Preparation for Shipment 94..............................

Table of Contents
iv P7380SMA 8 GHz Differential Probe Instruction Manual
List of Tables
Table 1: P7380SMA features 2..........................
Table 2: P7380SMA standard accessories 6................
Table 3: Optional accessories 8..........................
Table 4: Equipment required for functional checks 15.........
Table 5: Common-mode voltage and current table 39.........
Table 6: Differential to single-ended conversion table 55......
Table 7: Serial bus standards with
dynamic range requirements 63........................
Table 8: Warranted electrical characteristics 65..............
Table 9: Typical electrical characteristics 66................
Table 10: Nominal electrical characteristics 71..............
Table 11: Typical mechanical characteristics 71..............
Table 12: Equipment required for performance verification 73..
Table 13: P7380SMA probe compatibiity issues 91...........
Table 14: LED error conditions 92........................

Table of Contents
P7380SMA 8 GHz Differential Probe Instruction Manual v
List of Figures
Figure 1: P7380SMA differential probe 1..................
Figure 2: Connecting and disconnecting the probe 11..........
Figure 3: Probe signal input connections 12.................
Figure 4: Signal check setup 17...........................
Figure 5: Aux output check test setup 20....................
Figure 6: DC termination voltage check setup 22.............
Figure 7: Probe calibration setup 25........................
Figure 8: Using Auto Termination Voltage Control Mode 26....
Figure 9: Using External Termination Voltage Control Mode 27.
Figure 10: Using Internal Termination Voltage Control Mode 28.
Figure 11: Viewing the Aux Out signal on a spectrum analyzer 29
Figure 12: Using the probe with an 80A03 Interface and an 80A05
Module to view eye diagrams on a TDS8000 Series sampling
oscilloscope 31.....................................
Figure 13: P6150 probe tips 32............................
Figure 14: Simplified model of a differential amplifier 36......
Figure 15: Input termination network 37....................
Figure 16: Probe maximum input limits 42..................
Figure 17: Differential and Common-Mode operating ranges 43.
Figure 18: Termination voltage network drive 44.............
Figure 19: Overdrive Error indicator 47.....................
Figure 20: Differential measurement topology 48.............
Figure 21: 50 ohm termination on (--) input 51...............
Figure 22: Shorting termination on (--) input 52..............
Figure 23: Open (--) input 53.............................
Figure 24: Checking skew between inputs 57................
Figure 25: Using the phase adjuster 59.....................
Figure 26: Deskewing two P7380SMA probes 61.............
Figure 27: InfiniBand signals 64..........................
Figure 28: Typical CMRR plot 68.........................
Figure 29: Typical differential input return loss 69............
Figure 30: Typical differential-mode bandwidth 69............
Figure 31: Typical eye pattern from an InfiniBand signal 70....
Figure 32: Typical differential step response 70..............
Figure 33: Probe dimensions 72...........................
Figure 34: TekConnect-to-SMA Adapter 75.................
Figure 35: Preliminary test setup 76........................

Table of Contents
vi P7380SMA 8 GHz Differential Probe Instruction Manual
Figure 36: Checking differential mode input resistance 77......
Figure 37: Termination Voltage Accuracy, Ext mode setup 78...
Figure 38: Termination Voltage Accuracy, Auto mode setup 80..
Figure 39: Setup for the output offset zero test 82.............
Figure 40: DC Gain Accuracy setup 83.....................
Figure 41: Reverse the power supply polarity
on the probe inputs 84................................
Figure 42: Test system rise time setup 86...................
Figure 43: Setting the TDR parameters 87...................
Figure 44: Test system rise time setup with probe 88..........

P7380SMA 8 GHz Differential Probe Instruction Manual vii
Preface
This is the Instruction Manual for the P7380SMA differential probe.
This manual provides operating information, specifications, and
performance verification procedures for the probe.

Preface
viii P7380SMA 8 GHz Differential Probe Instruction Manual
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
www.tektronix.com/support
1-800-833-9200, select option 3*
6:00 a.m. -- 5:00 p.m. Pacific Standard 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.

P7380SMA 8 GHz Differential Probe Instruction Manual ix
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.
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 from the circuit under test
before disconnecting the probe from the measurement 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.
The common terminal is at ground potential. Do not connect the
common terminal to elevated voltages.
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.

General Safety Summary
xP7380SMA 8 GHz Differential Probe Instruction Manual
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.
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

P7380SMA 8 GHz Differential Probe Instruction Manual xi
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.

Service Safety Summary
xii P7380SMA 8 GHz Differential Probe Instruction Manual

P7380SMA 8 GHz Differential Probe Instruction Manual 1
Getting Started
The P7380SMA is an 8 GHz, active differential probe designed for
Serial Data Analysis (SDA) compliance testing and other applica-
tions that use differential serial busses in a 50 Ωsignaling environ-
ment. The SMA input connectors each terminate with an internal
50 Ωresistor. The internal 50 Ωresistors are not directly grounded,
but are driven by a buffer amplifier to a common-mode DC
termination voltage. The termination voltage range allows the
termination voltage to be set to any value within the specified
common mode voltage range of the input signal.
The DC termination voltage can be supplied either externally or
internally, including an automatic mode that sets the value of the
termination voltage to match the input signal DC common-mode
voltage. The P7380SMA probe has two selectable attenuator settings
that provide a tradeoff between dynamic range and noise. The
P7380SMA probe has been optimized for a clean pulse response for
accurate SDA compliance testing.
Figure 1: P7380SMA differential probe

Getting Started
2P7380SMA 8 GHz Differential Probe Instruction Manual
The probe incorporates the high-performance TekConnect interface
to communicate with the host instrument. In addition to the acquired
signal that is routed through the TekConnect interface, the probe also
provides a full-bandwidth, inverted-phase auxiliary output. The
auxiliary output can be used for additional signal analysis by
connecting it to a spectrum analyzer, network analyzer, or clock
recovery unit.
The probe is shipped with 50 Ωtermination caps connected to the
three SMA input and output connectors. When you are not using the
probe, leave the termination caps connected to protect the circuitry
from damage.
Always leave the Auxiliary output connector terminated when not in
use, to provide the best signal fidelity for the main probe output.
Probe Controls and Connections
Table 1 briefly outlines the controls and connections of the
P7380SMA differential probe. Additional information can be found
later in Getting Started and the following Operating Basics sections.
Table 1: P7380SMA features
Control/Connection Description
TekConnect interface. The TekConnect interface provides a
communication path between the probe and the oscilloscope.
Contact pins provide power, signal, offset, and probe characteris-
tic data transfer.
The probe snaps into the oscilloscope when fully engaged. To
remove, grasp the compensation box, press the latch button, and
pull the probe out.
For more information, see page 11.

Getting Started
P7380SMA 8 GHz Differential Probe Instruction Manual 3
Table 1: P7380SMA features (Cont.)
Control/Connection Description
Input signal connections. The SMA terminals provide shielded,
low-noise connections to your circuit. Differential or single-ended
signals are buffered by the internal probe amplifier and are sent
through the TekConnect interface to the oscilloscope.
See Probe Inputs on page 12 for more information.
External DC termination control voltage connections. The red
and black 0.080 in jacks on the end of the probe provide a means
for controlling the DC termination voltage with an external DC
power supply.
You should use the Banana-to-0.080 in plug adapter cables
included with the probe when connecting external control voltages
to these terminals.
The Overdrive Error LED glows continually red when the
termination voltage driver current exceeds its linear range.
In general, this will occur when the termination voltage differs from
the common-mode voltage by about 2.0 volts for zero-ohm source
impedances and about 4.0 volts for 50 ohm source impedances.
The Overdrive Error LED flashes when the termination voltage in
Auto Mode or EXT Mode exceeds the specified ±2.5 volt range by
about 10%.
The Overdrive Error LED clears when the range violation signal is
removed.
For more information, see pages 13 and 47.

Getting Started
4P7380SMA 8 GHz Differential Probe Instruction Manual
Table 1: P7380SMA features (Cont.)
Control/Connection Description
Attenuation/Dynamic Range Select and indicators. The Atten
Dynamic Range Select button allows you to select between 2.5X
and 12.5X probe attenuation settings. Note that the maximum
linear dynamic range for each attenuator setting is specified as a
differential peak-to-peak value.
The two indicator LEDs light briefly when the probe is powered
on, and then the 12.5X LED lights to indicate the 12.5X
attenuation is selected.1
If both LEDs flash, an internal probe diagnostic fault exists.
Disconnect and reconnect the probe to restart the power-on
diagnostic sequence. If the LEDs continue to flash, the probe is
defective, and must be returned to Tektronix for repair.
Termination Voltage Control Mode Select and indicators.
The V Term Source Select button allows you to select between
three termination voltage control modes—Auto, Internal, and
External. The three indicator LEDs light briefly when the probe is
powered on, and then the Auto LED lights.1
The probe initially sets to Auto mode; press the SELECT button to
choose another mode. The Auto Mode LED also flashes when the
probe signal inputs are AC-coupled or open-circuit. When this
happens, the termination voltage is set to 0.0 V.
In Auto mode, the input signal DC common mode voltage is
measured and the DC termination voltage is automatically set to
equal that voltage. This is the default mode setting when the
probe is powered on.
In Internal mode, the DC termination voltage is set with user
interface controls that are available on TekConnect-interface
oscilloscopes that support this mode. If your oscilloscope does not
support this mode, the termination voltage defaults to 0 volts.
In External mode, the DC termination voltage is controlled
indirectly with an external DC power supply connected to the
0.080 in pin jacks on the probe face plate. If these control voltage
inputs are left open, the termination voltage defaults to 0 volts.