TekVPI™Technology Delivers Versatility and
Ease-of-Use in a New Probe Interface Architecture
Technical Brief
TekVPI (Tektronix Versatile Probe Interface) architecture
obe
onix pr
oduces the next generation of T
intr
interface architecture with the announcement of a new
family of versatile, featur
obes designed for use with T
pr
e-rich, and easy-to-use T
ektr
ekVPI
ektronix newest
generation of DPO4000 and mid-range DPO7000 Series
DPO™ oscilloscope. The following article describes
the evolution of Tektronix probe interfaces, features of
ekVPI design, and the new T
T
ekVPI pr
obes.
ekVPI™ Delivers Versatility and Ease-of-Use in a New Probe Interface Architecture
T
Technical Brief
Evolution of Tektronix Probe Interfaces
Over the past 50 years a variety of oscilloscope probe
interface designs have evolved to support the require-
ments of increasing instrument bandwidth speeds and
measurement performance. In the earliest years banana
p
lug and UHF type connectors were commonly used.
During the early 1960’s plain BNC type connectors
became a common type of probe interface because of
the BNC’s smaller form factor and higher frequency
capabilities. BNC probe interfaces are still used today in
t
he design of test and measurement instruments with
today’s higher quality BNC type connectors providing
maximum useable bandwidth capabilities approaching
4 GHz.
In 1969 T
ektronix introduced a variation of the plain
BNC type of probe interface design with the introduction
of the 7000 Series probe interface architecture. 7000
Series designs used a BNC type connector for passing
the acquired analog signal, but additionally provided an
analog encoded scale factor detection pin as part of
the mechanical and electrical interface design which
enabled the compatible oscilloscope to automatically
detect and change the oscilloscope’s displayed vertical
attenuation range to incorporate the attenuation range
setting of the attached 7000 Series type probe.
In 1986 probe usability was further enhanced with the
introduction of the TekProbe™ probe interface architec-
ture. TekProbe-BNC Level 1 designs provided an analog
encoded scale factor detection pin to extend the attenu
ation ranges available in the 7000 Series interface and
ovide support for the legacy 7000 Series probes.
to pr
TekProbe-BNC Level 2 designs were also introduced to
support the required operating power requirements for
“active” probe types which contained transistors, IC’s,
or other active components as part of the probe’s signal
conditioning network design. TekProbe-BNC Level 2
further extended the capabilities of Level 1 designs by
adding probe communications with the oscilloscope to
improve the usability of increasingly sophisticated probe
types and to accomplish calibrated offset at the probe tip.
I
n 2001 the increasing advancement of Tektronix
probing capabilities coupled with the requirements for
ever-higher probe bandwidth, mechanical and electrical
design r
eliability and improved ease-of-use resulted in
the introduction of the TekConnect™ advanced probe
interface architecture providing optimum signal fidelity
and highest bandwidth. With maximum useable band-
width of TekProbe interface designs utilizing BNC
connectors limited to about 4 GHz the TekConnect
interface design ar
chitecture utilized a BMA type
connector (similar in size and performance to an SMA
connector) and capable of supporting high fidelity
electrical signal path performance up to at least 18 GHz
bandwidth in support of the capabilities of Tektronix
highest bandwidth oscilloscope. The TekConnect design
incorporated several mechanical design improvements
enabling convenient and reliable single-hand attachment
of a positive-locking TekConnect probe mechanism to
the oscilloscope. And, TekConnect design further
extended
the capabilities of pr
obe and oscilloscope
communication beyond read-only functions providing
read and write probe control functions which enabled
advanced featur
-
es such as electr
onic calibration
adjustment, soft switching of probe setup parameters,
cascading of other probe accessory adapters, etc.
Today, TekConnect design architecture continues to
represent the state-of-art in advanced probing capabilities
for Tektronix highest performance oscilloscopes.
2
22
2
www.tektronix.com/probes
ekVPI™ Delivers Versatility and Ease-of-Use in a New Probe Interface Architecture
Evolution of Tektronix Probe Interfaces
7000 Series (1969)Plain BNC (early 60s) TekProbe-BNC (1986)
TekConnect (2001)
Smaller and higher
performance than its
predecessor.
Introduced analog encoded
voltage scale factor detection
via a spring loaded pin.
Added power for active probes
and better communications
with the scope.
Addressed bandwidth limitations of
its BNC counterparts for optimal
signal integrety and improved
communications to high performance
scopes.
OUTPUT
G
ROUND
OUTPUT
DATA
GROUND
DATA
(7000-SERIES ONLY)
DATA(7000-SERIES ONLY )
DATA
-15 V
-
5 V
OFFSET
CLOCK
+5 V
+15 V
OUTPUT
GROUND
BROWN AREAS SHOW MALE
ACCESSORY PIN CONTACTING
L
OCATIONS ON HOST
TekVPI (2006)
TekVPI probe interface
architecture adds reliability and
improved communications to
mid-range performance scopes.
GROUND
OFFSET
NC
CLOCK
CASCADE
OUTPUT
GROUND
BMA SIGNAL CONNECTOR
SCOPE PAD ASSIGNMENTS
POWER AND
CONTROL
CONNECTOR
INT
DATA
+5 CON
-5
+15 V
-15 V
+5 V
+5 V
GND
ANALOG/SDA
BULK (~12V)
IRQ
CLK
OUTPUT
GROUND
T
Technical Brief
Figure 1.
Evolution of T
ektronix probe interfaces.
www.tektronix.com/probes
3
ekVPI™ Delivers Versatility and Ease-of-Use in a New Probe Interface Architecture
T
Technical Brief
Introducing TekVPI the Next Generation of
T
ektronix Probe Interface
In 2006 Tektronix introduced its newest generation of
Digital Phosphor Oscilloscopes: the DPO4000 and
mid-range models of the DPO7000 Series oscilloscope
families featuring TekVPI (Tektronix Versatile Probe
Interface) as the new probe interface architecture
designed to provide ease-of-use, versatility, and other
performance features important to users of this category
of oscilloscope. TekVPI leverages more than 50 years of
Tektronix probe product design experience combining
features and benefits of both the TekProbe and
TekConnect probe categories to create the new TekVPI
series of probes.
Features of TekVPI
Versatility and ease-of-use are the hallmarks of TekVPI
probe design, enabled by intelligent bi-directional oscil-
loscope/probe communications with its TekVPI
oscilloscope host instrument. TekVPI probe designs are
microprocessor based with EEROM memory and bi-
directional serial interface communications capability.
The design architecture of TekVPI provides users
improved ease-of-use in probe setup, easy selection
of displayed probe status and setup information, as well
as accurate probe measurement performance results all
intended to simplify and improve the performance of the
user’s test and measurement experience:
4
www.tektronix.com/probes
ekVPI™ Delivers Versatility and Ease-of-Use in a New Probe Interface Architecture
T
Technical Brief
TekVPI Probe Setups and User Interface
Each TekVPI probe features a rich set of probe compen-
sation box (“comp box”) located controls and indicators
designed to provide users quick and easy access to the
probe’s most commonly required setup controls and
operating status. Sealed membrane keypad buttons on
the probe’s comp box are clearly labeled and finger-
sized to enable user’s simple probe setup control.
Highly visible bi-color
ed or tri-colored LED indicator
lights on the probe’s comp box are clearly labeled to
provide the user easy to understand probe setup and
key operating status information.
Beyond the more traditional probe control and indicator
capabilities described above, TekVPI also introduces a
significant new feature for ease-of-use -- the Probe
Menu Button. All TekVPI probes feature a dedicated
probe comp box located Menu Button that enables
users to quickly and easily access a graphical pr
obe
menu display on the TekVPI host oscilloscope instrument.
The instrument probe menu display and other displayed
notification icons pr
ovide comprehensive probe informa-
tion including: Probe Model Type, Probe Serial Number,
Attached Probe Channel Number, Probe Operating
Status and Warnings, and Probe Diagnostics to aid
troubleshooting events. Additionally, all probe setup
control functions can be set, changed, or monitored
from the instrument display. To aid the users setup of
the applied test and measurement configuration, the
TekVPI host instrument also records and saves a setup
file (Save Setups) of probe configurations enabling
users to easily re-construct the test configuration
(Recall Setups) applied during their test application’
s
measurement acquisition.
TekVPI Probe Remote Control Support
Enabled by TekVPI’s bi-directional oscilloscope/probe
communications and the TekVPI host instrument’s net-
work communications capabilities (USB, GPIB, Ethernet)
TekVPI probe setups can be remotely controlled and
monitored to simplify the automation of testing applica-
tions in the user’s ATE environment. Remotely controlling
and changing setup functions like pr
obe attenuation
range, DC offset auto-zeroing, or degaussing the residual
magnetic fields in current probe types are all easily
accomplished with T
ekVPI assuring users of optimal
probe performance and measurement accuracy.
www.tektronix.com/probes
5
ekVPI™ Delivers Versatility and Ease-of-Use in a New Probe Interface Architecture
T
Technical Brief
Left to Right – Plain BNC or 7000 Series or T
and new T
ekVPI Legac
T
ekVPI connection
y Probe Support
ekProbe-BNC Level 1 connection; T
The evolution of Tektronix probe interfaces over the last
50 years has resulted in four distinct BNC legacy probe
interface types being applied with Tektronix oscilloscope
for applications up to 4 GHz in bandwidth: the BNC
connector
, 7000 Series, T
ekProbe-BNC Level 1, and
TekProbe-BNC Level 2 probe types.
ekProbe-BNC Level 2 connection via new TP
onix recognizes the importance of providing users
ektr
T
A-BNC adapter;
the versatility to apply legacy (or already owned) probe
types with T
ektronix newest generation of TekVPI
oscilloscope instruments. To protect the user’s previous
investments, TekVPI is designed to provide legacy probe
interface support for the plain BNC
connector, 7000 Series, TekProbe-BNC Level 1,
and T
obe-BNC Level 2 pr
ekPr
obe types.
6
www.tektronix.com/probes
ekVPI™ Delivers Versatility and Ease-of-Use in a New Probe Interface Architecture
T
– Plain BNC connected probes, 7000 Series probes,
and TekProbe-BNC Level 1 probes (types having the
single analog encoded scale factor detection pin) are
connected directly to the TekVPI probe channel input
connector on TekVPI oscilloscope. All performance
features and capabilities of these connected probe
types are supported and available to the user.
– TekProbe-BNC Level 2 probes are connected to the
TekVPI oscilloscope by using the new TPA-BNC
TekProbe-BNC to TekVPI probe interface adapter.
This adapter passes the attached TekProbe’s
acquired analog measurement signal thru a BNC
interface on the oscilloscope’s TekVPI probe channel
connector. Additionally, the TPA-BNC adapter converts
and supplies the required probe power resources
necessary for the operation of the attached
TekProbe-BNC Level 2 probe type. All performance
es and capabilities of the connected TekProbe-BNC
featur
Level 2 probe types are supported and available to
the user.
Technical Brief
TPA-BNC TekProbe-BNC Level 2 to TekVPI Probe Interface Adapter
www.tektronix.com/probes
7
ekVPI™ Delivers Versatility and Ease-of-Use in a New Probe Interface Architecture
T
Technical Brief
TekVPI Probe Power Management
The sophistication of modern “active probe” designs
required to provide probe communication, or to achieve
higher bandwidths necessary for accurately measuring
faster signaling rates, or to minimize probe loading
affects imposed upon the connected device under test,
or to provide “bucking currents” necessary to prevent
transformer core saturation and to extend the measure-
ment range of current measurement probe types all
generally require power resources to be externally
provided in support of the probe’s operation. “Active
probes” are probes containing transistors, or IC’s, or
other active components as part of the probe’s signal
conditioning network design. Traditionally, the power
resources necessary to support the operation of
active probes have been provided, allocated, and
managed by the designed-in capabilities of the host
oscilloscope instrument.
The design architecture of TekVPI provides a new
technique for probe power management enabling
several benefits and ease-of-use features for TekVPI
oscilloscope and probe users. The TekVPI host oscillo-
scope distributes +5 VDC and +12 VDC bulk power
supply resour
ces amongst the available TekVPI probe
input channel connections of the instrument. Since each
obe input channel has equal access to the bulk power
pr
supply resources no input channel is restricted to what
probe type may be connected to that channel or what
combination of probe types may be configured to the
oscilloscope. The infrastructure for probe power
management and the necessary voltage conversions to
support the power resource requirements of individual
probe types is performed within each TekVPI probe
and not within the host oscilloscope. This distributed
architecture of probe power management as accom-
plished within the TekVPI probes reduces the design
overhead and associated costs of the TekVPI
host oscilloscope.
One example illustrating the significant benefit of
TekVPI’s probe power management design is found with
the new TCP0030, 30 Ampere AC/DC current probe.
Traditionally, current probes of this measurement range
required external power supplies to provide the neces-
sary resources required for “bucking currents” and to
perform degaussing operations necessary to maintain
accurate measurement capability. The TCP0030 TekVPI
current probe now eliminates this need for an external
power supply. The TCP0030 simply connects directly to
any probe input channel on a TekVPI host oscilloscope,
reducing the complexity of the user’s test equipment
configuration, and saving the user valuable bench space.
8
www.tektronix.com/probes
ekVPI™ Delivers Versatility and Ease-of-Use in a New Probe Interface Architecture
T
Technical Brief
TekVPI Mechanical Design
TekVPI probes provide attractive and ergonomically
designed packaging and a reliable mechanical interface
design. The TekVPI probe or adapter attachment is
made by inserting the nose piece of the probe connector
into the mating bucket of the TekVPI oscilloscope probe
input channel connector. A spring-assisted pull-in force
on the bucket side of the interface assures a reliable
connection, and a lock mechanism in the interface
nose piece securely retains the attachment until release
is desired. TekVPI probe or adapter attachment and
release is an easy single-handed user operation in which
a thumb push-button lock release is pressed at the
same time the TekVPI probe or adapter is either to be
attached or r
eleased. To assure electrical signal integrity
of the probe interface connections gold-plated spring-
contact pins on the TekVPI probe or adapter nose piece
mate with gold-plated contact pads on a small cir
cuit
board on the TekVPI oscilloscope’s probe input channel
bucket side.
TekVPI Embeds the Probes Characteristics
within the Oscilloscope
Enabled by the microprocessor, memory, and bi-direc-
tional communications capabilities of the TekVPI probe,
tighter integration between the oscilloscope and the
connected TekVPI probe is now possible to compensate
for known gain offsets or propagation delays characteristic
of the connected TekVPI probe type. This capability
provides users easy-to-use and more accurate probe
measurement results.
One example of this TekVPI probe design benefit concerns
propagation time delay parameters measured during
TekVPI probe manufacturing and stored within the
probe’s memory for later use by the connected TekVPI
oscilloscope. De-skewing of signal delay timing differ-
ences between voltage and current measurement probe
types for accurate power measur
ement analysis results
is an important but sometimes difficult to accomplish
or even a neglected step of the testing setup. TekVPI
probes communicate their stored propagation time
delay characteristics to their host TekVPI oscilloscope
and this information is then used to achieve de-skewed
time alignment within less than 1 nanosecond of accuracy
for the measured voltage and current signals waveform
phase relationship. (More precise timing de-skew
capabilities are achievable using an external de-skew
calibration accessory fixture.)
www.tektronix.com/probes
9
ekVPI™ Delivers Versatility and Ease-of-Use in a New Probe Interface Architecture
T
Technical Brief
T
T
CP0030
AP2500 (and typical of TAP1500)
New TekVPI Probe Types
At product introduction in 2006 the initial TekVPI probe
ferings are summarized as follows: (Refer to
type of
individual product datasheets for specifications, illustrations,
applications, and features & benefits descriptions.)
TCP0030 - AC/DC Current Probe
–
ectly connects to TekVPI oscilloscope
- Dir
- 1mA to 30A measur
ement range
- >120 MHz bandwidth
- 50A peak pulse capability
–
TAP1500 - 1.5 GHz Active Voltage Probe
- ≤ 267 ps rise time
- ± 8V input dynamic range
- ≤ 1 pF input capacitance
- 1 MΩ input r
esistance
- Compact probe head for accessing small
design geometries
TAP2500 - 2.5 GHz Active Voltage Probe
–
- <140 ps rise time
- ± 4V input dynamic range
- ≤ 0.8 pF input capacitance
- 40 kΩ input resistance
- Compact pr
obe head for accessing small
design geometries
10
www.tektronix.com/probes
ekVPI™ Delivers Versatility and Ease-of-Use in a New Probe Interface Architecture
T
Technical Brief
www.tektronix.com/probes
11
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Last Updated June 15 2005
For Further Information
onix maintains a comprehensive, constantly expanding collection
ektr
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Copyright © 2005, Tektronix, Inc. All rights reserved. Tektronix products are covered by U.S. and foreign
patents, issued and pending. Information in this publication supersedes that in all previously
published material. Specification and price change privileges reserved. TEKTRONIX and TEK are
r
egistered trademarks of Tektronix, Inc. All other trade names referenced are the service marks,
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egister
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