Tektronix TDP7704, TDP7706, TDP7708, TDP7710 Specification and Performance Verification

TDP7700 Series
TriMode™ Probes

Technical Reference

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TriMode and TekFlex are trademarks of Tektronix, Inc.

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14150 SW Karl Braun Drive

P.O. Box 500

Beaverton, OR 97077

USA

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Table of Contents

Table of Contents

List of Figures............................................................................................................................................................................... iv

List of Tables................................................................................................................................................................................. v

Important safety information......................................................................................................................................................... vi

General safety summary....................................................................................................................................................... vi

Terms in the manual.............................................................................................................................................................. vi

Terms on the product............................................................................................................................................................vii

Symbols on the product........................................................................................................................................................vii

Theory of operation....................................................................................................................................................................... 1

Introduction............................................................................................................................................................................ 1

Probe components..........................................................................................................................................................1

Probe tips........................................................................................................................................................................2

Probe input architecture.........................................................................................................................................................4

TriMode operation..................................................................................................................................................................7

Operating voltages.................................................................................................................................................................8

Max non-desctruct input voltage.....................................................................................................................................9

Input signal dynamic range.............................................................................................................................................9

Offset voltage................................................................................................................................................................10

Operating voltage window.............................................................................................................................................12

Improving measurement accuracy.......................................................................................................................................14

DSP correction filtering................................................................................................................................................. 14

Solder-in tip connection wire length..............................................................................................................................14

Using offset voltage to extend TekFlex® solder-in tip input voltage range................................................................... 17

Making single ended measurements using the P77BRWSR differential probe tip....................................................... 18

Temperature compensation.......................................................................................................................................... 18

Active tip measurement configuration...........................................................................................................................18

Skew measurements of differential signals...................................................................................................................18

Reference....................................................................................................................................................................................20

Differential measurements................................................................................................................................................... 20

Common-mode rejection ratio.......................................................................................................................................20

Assessing CMRR error................................................................................................................................................. 21

Input impedance effects on CMRR...............................................................................................................................21

Differential-mode rejection............................................................................................................................................21

Channel isolation.......................................................................................................................................................... 21

Impedance graphs .............................................................................................................................................................. 25

Nominal characteristics........................................................................................................................................................27

Environmental...................................................................................................................................................................... 27

Performance verification............................................................................................................................................................. 29

Test record........................................................................................................................................................................... 29

Check system noise.............................................................................................................................................................29

Index........................................................................................................................................................................................... 30

TDP7700 Series TriMode™ Probes Technical Reference iii

List of Figures

List of Figures

Figure 1: TDP7700 Series TriMode probe components................................................................................................................1

Figure 2: TekFlex active probe tips............................................................................................................................................... 3

Figure 3: P77C292MM adapter.....................................................................................................................................................3

Figure 4: TDP7700 Series TriMode probe input architecture........................................................................................................4

Figure 5: TDP7700 Series TriMode probe input architecture with the P77C292MM SMA adapter.............................................. 7

Figure 6: TriMode input structure.................................................................................................................................................. 8

Figure 7: TekFlex probe tip inputs.................................................................................................................................................9

Figure 8: Simplified diagram of the TekFlex probe tip input network...........................................................................................10

Figure 9: Simplified Auto Tracking circuitry ................................................................................................................................ 11

Figure 10: Operating voltage window (TekFlex solder-in tips).................................................................................................... 12

Figure 11: Operating voltage window (diferential mode, flex tip).................................................................................................12

Figure 12: Operating voltage window (common mode, flex tip).................................................................................................. 13

Figure 13: Operating voltage window (P77C292MM SMA adapter)........................................................................................... 13

Figure 14: Operating voltage window (differential mode, P77C292MM adapter)........................................................................13

Figure 15: Operating voltage window (common mode, P77C292MM adapter).......................................................................... 13

Figure 16: P77STFLXA solder tip attached with 10 mils (0.250 mm) wires (rise time = 30.5 ps)............................................... 15

Figure 17: P77STFLXA solder tip attached with 75 mils (1.90 mm) wires (rise time = 27.9 ps)................................................. 15

Figure 18: P77STFLXA solder tip attached with 120 mils (3.05 mm) wires (rise time = 30.1 ps)............................................... 16

Figure 19: P77STFLXA solder tip attached with 200 mils (5.08 mm) wires (rise time = 34 ps).................................................. 16

Figure 20: P77STFLXA solder tip attached with 300 mils (7.62 mm) wires (rise time = 42.8 ps)............................................... 16

Figure 21: Simplified diagram of the TekFlex probe tip input network.........................................................................................17

Figure 22: Active tip measurement configuration........................................................................................................................18

Figure 23: Example of LVDS differential signal........................................................................................................................... 19

Figure 24: Simplified model of a differential amplifier..................................................................................................................20

Figure 25: Typical CMRR............................................................................................................................................................21

Figure 26: Typical channel isolation............................................................................................................................................22

Figure 27: P77STCABL differential impedance...........................................................................................................................25

Figure 28: P77STCABL SE impedance ..................................................................................................................................... 26

Figure 29: P77STFLXA differential impedance...........................................................................................................................26

Figure 30: PST77FLXA SE impedance.......................................................................................................................................26

Figure 31: P77BRWSR differential impedance........................................................................................................................... 27

TDP7700 Series TriMode™ Probes Technical Reference iv

List of Tables

List of Tables

Table 1: Probe tip attenuation factors............................................................................................................................................5

Table 2: Rise time and overshoot degradation versus lead length..............................................................................................17

TDP7700 Series TriMode™ Probes Technical Reference v

Important safety information

This manual contains information and warnings that must be followed by the user for safe operation and to keep the product
in a safe condition.

General safety summary

Use the product only as specified. Review the following safety precautions to avoid injury and prevent damage to this
product or any products connected to it. Carefully read all instructions. Retain these instructions for future reference.

This product is not intended for detection of hazardous voltages.

To avoid fire or personal injury

Observe all terminal ratings To avoid fire or shock hazard, observe all rating and markings on the product.

Consult the product manual for further ratings information before making connections
to the product.

Do not apply a potential to any terminal, including the common terminal, that
exceeds the maximum rating of that terminal.

Do not operate without covers Do not operate this product with covers or panels removed, or with the case open.

Hazardous voltage exposure is possible.

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 installation instructions in the manual for details on installing the product

Be aware that condensation may occur if a unit is moved from a cold to a warm
environment.

Remove the input signals before you clean the product.

so it has proper ventilation.

Slots and openings are provided for ventilation and should never be covered or
otherwise obstructed. Do not push objects into any of the openings.

Important safety information

Probes and test leads

Remove all probes, test leads and accessories that are not in use.

Inspect the probe and
accessories

Before each use, inspect probe and accessories for damage (cuts, tears, or defects
in the probe body, accessories, or cable jacket). Do not use if damaged.

Use only specified replacement parts.

Terms in the 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.

TDP7700 Series TriMode™ Probes Technical Reference vi

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

The following symbols may appear on the product:

Important safety information

TDP7700 Series TriMode™ Probes Technical Reference vii

Important safety information

TDP7700 Series TriMode™ Probes Technical Reference viii

Theory of operation

Introduction

The TDP7700 Series TriMode Probes are designed for use with 6 Series MSO and newer oscilloscopes. Three TDP7700
Series TriMode Probe models are available with bandwidths from 4 GHz to 10 GHz. 6 Series MSO oscilloscope models are
available at comparable bandwidths. These probe and oscilloscope models feature the high performance TekVPI intelligent
probe interface. Several TekFlex tip models are available to support different application requirements.

The TDP7700 Series probes and probe tips contain device-specific S-parameter data that, when transferred to the host
oscilloscope after the initial connection is made, create unique system DSP filters. These DSP filters optimize high
frequency performance of the probe and probe tip signal path.

The TekFlex connector allows for quickly changing tip accessories with a simple pinch to open operation. Accessories
include small solder-in tips for accessing high speed signals in tight spaces, a 2.92 mm adapter for connecting to fixtures
and pre installed test points and a high bandwidth adjustable browser for debugging and non permanent connections.

Theory of operation

Figure 1: TDP7700 Series TriMode probe components

Probe components

TDP7700 Series probes are comprised of a probe compensation box (comp box), a TekFlex connector for attaching probe
tips, and an interconnect cable that transfers measured signals, power, and control signals between the probe comp box
and the TekFlex connector probe head. A TekFlex probe tip must be inserted into the TekFlex connector probe head to
make the final connection to the DUT (device under test).

Probe compensation box

The probe compensation box assembly mates to the host instrument through an intelligent FlexChannel probe interface.
Power, control signals, and the signal measured by the probe are transferred to and from the oscilloscope through the
FlexChannel interface. The comp box includes a button to select the TriMode input mode for probe tips that support TriMode
functionality: (For more information see TriMode operation on page 7.)

TDP7700 Series TriMode™ Probes Technical Reference 1

Theory of operation

• Differential (A–B)

• A input (single-ended to ground)

• B input (single-ended to ground)

• Common-mode ((A+B)/2 to ground)

The probe input mode can also be selected using the oscilloscope Probe Setup configuration menu. The Probe Setup
configuration menu is also used to adjust the probe Differential offset, Common mode offset, A side offset and, B side offset
voltage settings. All other TDP7700 Series probe internal controls, such as vertical scaling, are handled automatically
through communication between the probe and oscilloscope.

CAUTION: To prevent damage to the probe, use care when handling the probe. Rough or careless use can
damage the probe.

LED indicators

There is a Status indicator LED located on the top plate of the probe comp box. This LED is normally green, but turns red
when any of the following conditions exist and remains red until the problem condition is cleared:

• Probe power-on self-test failure (clear by disconnecting and reconnecting the probe)

• Probe over-temperature detected (clear by disconnecting and reconnecting the probe, allowing time for probe to cool)

• Probe input over-voltage detected (reduce input over-voltage to clear)

• Probe over current detected (adjust V

or remove input signal to clear)

term

If the LED is red, disconnect and reconnect the probe to restart the power-on diagnostic sequence. If the symptoms
continue, connect the probe to another oscilloscope channel or oscilloscope. If the symptoms remain, return the probe to
Tektronix for repair.

Main interconnect cable

This cable assembly consists of a pair of matched, low-loss coaxial signal cables that carry the acquired signal from the
probe head to the probe comp box. The cable assembly includes an 8-conductor bundle of wires that supply probe tip head
power and control signals from the probe comp box through the TekFlex connector interface. Some of the wires carry
bidirectional data, such as queries and responses about the type of probe tip attached to the TekFlex connector, and other
probe tip-specific information.

TekFlex™ connector

The new TekFlex connector technology combines a high speed signal path with low speed control signaling in a single, easy
to connect accessory connector. The TekFlex connector has a pinch-to-open design that when open requires minimal force
to attach an accessory tip. When the TekFlex connector is closed, it provides a secure connection to the accessory to avoid
accidental disconnections.

The connector provides a light-weight electrical and mechanical interface between a TDP7700 Series probe and a TekFlex
active probe tip. It contains a spring-loaded set of electrical contacts that connect between the main cable wiring and
contact patterns on the attached probe tip. There is a differential, high-frequency contact pattern on the top of the probe tip
that connects the probe tip dual signal inputs and grounds to the probe main cable coaxial pair. There is also an eight-finger
contact pattern on the bottom of the probe tip that connects the probe tip power and control signals to a ribbon wire in the
main cable. The TekFlex connector provides mechanical alignment between a keyed hole pattern on the probe tip and a pair
of pins inside the spring loaded connector housing.

With the TekFlex connector, the TDP7700 series probes offer a set of active probe tips with the probe's buffer amplifier only
millimeters from the input connections. The short signal path enabled with the active tips provides high fidelity and a high
impedance input. It minimizes signal loss, capacitance, and additive noise.

Probe tips

The probe tips are automatically detected and displayed in the Probe Setup configuration menu.

TDP7700 Series TriMode™ Probes Technical Reference 2

Figure 2: TekFlex active probe tips

TekFlex solder-in tips

These tips use flex circuit material and provide soldered, multi-point connections. They support full TriMode measurement
capabilities and full probe bandwidth. If care is taken during the soldering process, these probe tips can be reused through
multiple soldering operations. The small size and low cost design are good for high interconnect density measurements.

Both P77STFLXA Flex circuit based solder tips and P77STFLXB Flex circuit based DDR memory solder tips are available.

The first time the probe tip is detected, S-parameter data for the probe tip is sent to the oscilloscope, and probe-tip specific
DSP filters are generated. These filters improve the measurement accuracy of high-frequency measurements.

P77STCABL

Theory of operation

This optional tip provides a soldered, multi-point connection that supports full TriMode measurement capabilities at full
probe bandwidth. If care is taken during the soldering process, this probe tip can be reused through multiple soldering
operations. In some applications the robust mechanical design of the tip and flexible cable construction provides better
usability, compared to the lower cost flex circuit tips. The first time the probe tip is detected, S-parameter data for the probe
tip is sent to the oscilloscope, and probe-tip specific DSP filters are generated.

P77BRWSR

The optional browser connects to the circuit using two input contacts with very fine point tips. These tips have built-in
compliance 0.02 in (0.5 mm) and adjustable spacing 0.008 in to 0.210 in (0.2 mm – 5.3 mm). The input contacts include an
embedded damping resistor for optimum measurement performance.

The browser tip can be held in place or can be used to make hands-free connections to the DUT when using the Browser
Tri-Pod accessory, or a probe positioner, such as the Tektronix PPM203B. The browser includes multiple sets of S­parameters based on the spacing of the tips. The spacing is monitored and the correct set of S-parameters are
automatically used.

P77C292MM adapter

Use the P77C292MM, 2.92 mm adapter to connect a TDP7700 series probe to a DUT with 50 Ω test point connectors. 2.92
mm connectors are mechanically compatible with SMA connectors.

Figure 3: P77C292MM adapter

The adapter supports testing of serial standards such as HDMI, MIPI M-PHY, and DisplayPort; cables and retainer are
included.

TDP7700 Series TriMode™ Probes Technical Reference 3

After connecting the adapter to the flex cable, use the retainer to provide a secure connection to the flex cable to minimize
movement or to attach the adapter to the hand’s free tripod.

For stacking more than one adapter, use the linkage adapter accessories to secure the P77C292MM adapters together.

Probe input architecture

Input architecture

TDP7700 Series probes feature a new probe architecture that addresses the need for high frequency response with
decreased probe loading for high-speed, low power applications such as MIPI® and LPDDR. High performance probes with
multi-GHz bandwidth have evolved in recent years, starting from traditional designs with metal pin tips attached to a probe
head amplifier located at the end of a coaxial cable. As the probe bandwidth extended to 10 GHz and above, probe designs
migrated to connectorized amplifier input structures that supported a variety of high frequency passive probe tips, including
solderable tip designs. These probe tips typically provide a passive input attenuator network at the probe tip followed by a
long cable attached to the probe amplifier connection socket. Although these passive tip, probe designs enable good, high
frequency performance, they show higher probe loading in the frequency band below 1 GHz than earlier traditional designs
with an amplifier closer to the probe tip. A probe with this higher loading characteristic below 1 GHz has problems when
taking measurements of signals such as MIPI that can be switched to an unterminated, high impedance mode for low power
operation. The TDP7700 Series probe solves this loading problem by introducing an active probe tip design with a tiny
buffer amplifier located near the tip inputs. By locating an amplifier with a high impedance attenuator network at the probe
tip inputs, the probe tip parasitic capacitance can be kept much lower than passive cable tip designs, thus reducing probe
loading in the low power signaling frequency band used by serial data standards such as MIPI.

Theory of operation

The following figure shows a simplified diagram of the TekFlex active probe tip architecture.

Figure 4: TDP7700 Series TriMode probe input architecture

The TekFlex active probe tip has two inputs, A_IN and B_IN, which can, depending on the tip design, support TriMode
measurements. With a TriMode tip, such as a TekFlex solder-in tip, it is possible to make differential, single-ended A, single­ended B, and common-mode measurements, all from a single soldered differential signal connection to a DUT. The
soldered wire connections between the two probe tip input signal vias and DUT differential signal nodes should be kept as
short as possible (as should the ground via connections if single-ended measurements will be made). The A and B input
signals on the probe tip pass to a matched pair of damping resistors, Rd, that isolate the probe connection to the DUT. The

TDP7700 Series TriMode™ Probes Technical Reference 4