Teledyne Lecroy HVFO103 User manual

Operator’s Manual
HVFO103
High
-Voltage
Fiber Optically Isolated Probe

HVFO103
High-Voltage Fiber Optically Isolated Probe
Operator’s Manual
January, 2019

HVFO103 High-Voltage Fiber Optically Isolated Probe Operator's Manual
© 2019 Teledyne LeCroy, Inc. All rights reserved.
Unauthorized duplication of Teledyne LeCroy documentation materials is strictly prohibited.
Customers are authorized to duplicate and distribute Teledyne LeCroy documentation for
internal training purposes.
Teledyne LeCroy is a trademark of Teledyne LeCroy, Inc. Other product or brand names are
trademarks or requested trademarks of their respective holders. Information in this publication
supersedes all earlier versions. Specifications are subject to change without notice.
929785-00 Rev A
January, 2019

Operator’s Manual
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Contents
Safety.............................................................................................................................1
Symbols .............................................................................................................................1
General Precautions..........................................................................................................1
High Voltage Precautions.................................................................................................2
Safety Ratings for Accessories........................................................................................3
Safe Operating Environment ............................................................................................4
Introduction....................................................................................................................5
Key Features......................................................................................................................5
Method of Operation .........................................................................................................5
Probe Design Compared to a Differential Probe.............................................................6
Effect of Tip Design on Current Paths .............................................................................8
Compatibility......................................................................................................................9
Required Firmware Versions ............................................................................................9
HVFO Probe System .....................................................................................................10
HVFO103..........................................................................................................................10
Attenuating Tips (one required) .....................................................................................11
Optional Accessories ......................................................................................................11
HVFO103 Probe Specifications ....................................................................................12
Specifications..................................................................................................................12
Electrical Characteristics................................................................................................12
Vertical Sensitivity...........................................................................................................13
Amplifier/Modulating Transmitter Battery....................................................................13
Dimensions ......................................................................................................................13
Bandwidth ........................................................................................................................14
Common Mode Rejection Ratio .....................................................................................15
Input Impedance..............................................................................................................16
Operation .....................................................................................................................17
Assembling the Probe.....................................................................................................17
Connecting to the Test Circuit........................................................................................18
Connecting to the Test Instrument................................................................................20
Operating with an Oscilloscope .....................................................................................20

HVFO103 High-Voltage Fiber Optically Isolated Probe
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Recharging the Amplifier/Modulating Transmitter ......................................................22
Performance Verification..............................................................................................23
Required Test Equipment ...............................................................................................23
Functional Check.............................................................................................................24
Before You Begin.............................................................................................................24
Performance Verification Test Setup ............................................................................25
Check Gain Accuracy ......................................................................................................25
Adjust Gain Accuracy.....................................................................................................26
HVFO103 Performance Verification Test Record ..........................................................27
Care and Maintenance..................................................................................................28
Cleaning the Probe Body ................................................................................................28
Cleaning the Optical Ports..............................................................................................28
Cleaning the Fiber Optic Cable .......................................................................................28
Replacing the Transmitter Battery.................................................................................28
Calibration Interval ..........................................................................................................28
Service Strategy ..............................................................................................................28
Attenuating Tip Compensation ......................................................................................29
Returning a Product for Service.....................................................................................30
Technical Support ...........................................................................................................31
Reference.....................................................................................................................32
Common Mode Rejection Ratio ....................................................................................32
Common Mode Range ....................................................................................................33
IEC/EN 61010-031:2015 Definitions ..............................................................................33
Warranty...........................................................................................................................34
Certifications ...................................................................................................................35

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Safety
Follow these instructions to keep the probe operating in a correct and safe condition. Observe
generally accepted safety procedures in addition to the precautions specified here. The overall
safety of any system incorporating this accessory is the responsibility of the system owner.
Symbols
These symbols appear on the probe and accessories or in this manual to alert you to important
safety considerations.
WARNING, HIGH VOLTAGE. Risk of electric shock or burn.
CAUTION of damage to probe or instrument, or WARNING of hazard to health. Attend to the
accompanying information to protect against personal injury or damage. Do not proceed until
conditions are fully understood and met.
ESD CAUTION. Risk of Electrostatic Discharge (ESD) that can damage the probe or instrument
if anti-static measures are not taken.
Laser Safety WARNING.
General Precautions
To avoid personal injury or damage to your equipment:
Use only as specified. The probe is intended to be used only with compatible Teledyne LeCroy
instruments. Using the probe and/or the equipment it is connected to in a manner other than
specified may impair the protection mechanisms.
Do not overload; observe all ratings. Do not connect the probe to any circuit that exceeds the
ratings of the oscilloscope terminal, probe, or probe-accessory combination.
Use only accessories compatible with the probe. Use only accessories that are rated for the
application. Substituting other accessories than those specified in this manual may create an
electrical hazard.
Connect and disconnect properly. Connect the probe to the measurement instrument before
connecting to the circuit being measured. Avoid excessive bending that can damage cables.
Keep the probe body and output cable away from the circuits being measured. Only tips are
intended for contact with electrical sources.
Do not use the probe for measurements on Mains circuits. This probe does not have a CAT
rating for use on these types of circuits.

HVFO103 High-Voltage Fiber Optically Isolated Probe
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Except for gain accuracy adjustment, do not remove the probe's casing. Touching exposed
connections may result in electric shock.
Use only indoors and within the operational environment listed. Do not use in wet or explosive
atmospheres.
Keep product surfaces clean and dry.
Handle with care. Probe tips are sharp and may cause injury if not handled properly.
Do not operate with suspected failures. Before each use, inspect the probe and accessories for
damage such as tears or other defects in the body, cable jacket, etc. If any part is damaged,
cease operation immediately and sequester the probe from inadvertent use.
High Voltage Precautions
To avoid injury or death due to electric shock or burn:
Do not handle probe tips, leads or any part of the amplifier/modulating transmitter at any time if
DC bus voltages are >60 V.The probe is not rated for hand-held use above 60 V. If there is any
question as to whether >60 V voltages are present in the circuit, use caution and DO NOT touch
these components.
Always ensure that, when not hand-held, the amplifier/modulating transmitter and attached tip
are positioned to maintain adequate spacing between these two components and earth ground.
Some of the probe components float at the common-mode voltage and some do not. The
spacing requirements depend on the common-mode voltage present in the test setup.

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Safety Ratings for Accessories
Accessory
Part Number
CAT Rating*
Max. Input Voltage Probe &
Accessory (input to ground)
1x Attenuating Tip
HVFO100-1X-TIP-U
No Rated Measurement Category
+/-1 V (DC + Peak AC)
(5 V maximum non-destruct)
5x Attenuating Tip
HVFO100-5X-TIP-U
No Rated Measurement Category
+/-5 V (DC + Peak AC)
(25 V maximum non-destruct)
10x Attenuating Tip
HVFO100-10X-TIP-U
No Rated Measurement Category
+/-10 V (DC + Peak AC)
(50 V maximum non-destruct)
20x Attenuating Tip
HVFO100-20X-TIP-U
No Rated Measurement Category
+/-20 V (DC + Peak AC)
(100 V maximum non-destruct)
40x Attenuating Tip HVFO100-40X-TIP-U No Rated Measurement Category +/-40 V (DC + Peak AC)
(100 V maximum non-destruct)
* Per IEC/EN 61010-031:2015. See definitions on p.33.

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Safe Operating Environment
Temperature, Operating 0° C to 50° C
Temperature, Charging 0° C to 40° C
Temperature, Non-operating -20° C to 70° C
Relative Humidity, Operating 5% to 80% RH (Non-Condensing)
45% RH above 30 C
Relative Humidity, Non-operating 5% to 95% RH (Non-Condensing)
75% RH above 30 C
45% RH above 40 C
Altitude, Operating 3000 m (9842 ft.) maximum
Altitude, Non-Operating 10,000 m (32,807 ft.) maximum
Usage Indoor Use Only
Pollution Degree 2*
* Per IEC/EN 61010-031:2015. See definitions on p.33.
The SAC-01 case and packaging materials shipped with the probe may not be suitable
for certain ESD sensitive areas, such as EPAs (ESD Protected Areas). If this is a
concern for your application, please take the necessary steps required for your test
environment.
.

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Introduction
The HVFO103 High Voltage Fiber Optically-isolated probe is an affordable, optimally designed
probe for measurement of small signals floating on an HV bus in power electronics designs, or
for EMC, EFT, ESD, and RF immunity testing sensor monitoring. It far surpasses the
measurement capabilities and signal fidelity of conventional high attenuation, high voltage
differential probes and acquisition systems that rely on galvanic channel-channel and channel-
ground high voltage isolation. Furthermore, it mitigates the need to rely on dangerous test
setups that require floating the oscilloscope and probe.
Key Features
•35 kV common-mode voltage rating (fiber optic isolation)
•Signal voltage measurement range from +/-1 V to +/-40 V with selectable tips
•Superior noise and rejection:
o>100 dB common mode rejection ratio (CMRR)
oLow loop inductance
oLow attenuation
•60 MHz bandwidth
•2% DC and low-frequency gain accuracy
•ProBus interface with automatic scaling
•Auto Zero capabilities
Method of Operation
The low-attenuation tip makes a three-wire (Signal, Reference, and Shield) electrical connection
to the device under test (DUT). The Signal connection wire is coaxial and attaches to the high
side of the signal measurement. The Reference wire and Shield wires are non-coaxial and attach
to the low side of the signal measurement. The Reference wire carries the signal return current,
while the Shield wire carries the current that is associated with the stray parasitic capacitances.
The output of the tip is input to the transmitter where an integrated, low-noise electrical amplifier
amplifies the attenuated signal, which is then frequency modulated in optical form for transmission
across the fiber optic cable. A subcarrier to the main modulation signal carries tip identifying
information so that attenuation and voltage scaling can be communicated to the oscilloscope.
The receiver demodulates the fiber optic signal to an electrical signal for input to the
oscilloscope. The subcarrier tip attenuation information is communicated through the
oscilloscope ProBus interface for proper voltage scaling.

HVFO103 High-Voltage Fiber Optically Isolated Probe
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Probe Design Compared to a Differential Probe
When properly used in its intended application, the HVFO103 will achieve much better results
than a conventional, high-attenuation HV differential probe due to the dramatically different
probe design.
Consider the case where a conventional, high-
attenuation HV differential probe is connected
in-circuit to measure a small signal floating on
a HV DC bus (left).
•The differential leads are connected across a sense resistor at a voltage VSthat is
floating above ground by the DC bus common-mode (VCM) voltage. The probe must use
high attenuation to reduce the measured voltage (VCM+VS) to a low enough level to use
safely with an oscilloscope.
•The two input leads are connected across the low voltage VS, but due to the probe
construction, these leads are actually measuring VSand (VCM+VS), and the difference
between them is VS.
•The high VCM value (typically 500 to 1000 VDC) results in large current flows (based on
the proportion of RLEAD to RSENSE) when RLEAD is not >> RSENSE. These large current flows
may load the circuit and inhibit proper DUT operation.
•The input lead capacitance CLEAD has a very high voltage (either VCM or VCM+VS), which
will result in a large capacitive charging current that will further load the DUT and likely
affect the fidelity of the measured signal. These limitations are inherent in this design.
•The high attenuation requires that the oscilloscope be operated in a very high sensitivity
(small V/div) setting, which results in higher gain and more noise on the signal―often
enough to make the measurement nearly unusable.

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•Since the probe is connected to ground, the common mode rejection ratio (CMRR, p.32)
of the differential amplifier in the probe must be very good or else signal noise and
interference will not be rejected and will add to measurement noise. High enough CMRR
is difficult and costly to accomplish, since it requires very precise matching of the + and
– probe input leads and excellent amplifier design.
Now, consider the advantages of the HVFO
design in a circuit where the HVFO tip wires
are connected only across VS(left).
•The VCM has no impact on the loading of the circuit, since the RLEAD >> RSENSE.
•The small CLEAD requires minimal charging current, since the voltage VSis very low
(volts, not hundreds of volts or kilovolts).
•The tip attenuation is very low, so the signal is not being highly attenuated and then
highly amplified by oscilloscope, which would result in higher noise.
•The CMRR can easily be made very high, since there is no requirement to identically
match a differential lead pair, and the high CMRR performance is inherent in the fiber
optic isolation from ground.
In the example above, the HVFO will perform better than a conventional, high-attenuation HV
differential probe when some or all of the following are true:
•Common mode voltages (VCM) are higher –170VDC or more.
•DUT impedance is lower.
•Signal rise times are faster (within the limitation of the probe bandwidth).
•Switched energy is higher.

HVFO103 High-Voltage Fiber Optically Isolated Probe
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It is unlikely that the HVFO103 will show much improvement on a very low voltage DC bus (~20 V)
floating signal unless the rise time is very fast. However, with typical 120/240 VAC supplied
equipment (340-500 VDC bus voltage), 600 VAC class equipment (1000 VDC bus voltage), or ≥ 5 k VAC
class equipment, the advantages of the HVFO will be obvious, in most cases.
Effect of Tip Design on Current Paths
The HVFO103 three-wire tip provides
optimal measurement results by separating
the signal return currents from the currents
associated with the probe stray parasitic
capacitance. This reduces the noise
measured in the system, and improves the
CMRR performance of the probe.
The image at left shows how the tip
construction affects the current paths.
•The blue Signal wire conducts the Signal current, which follows a return path through
the green Reference wire.
•The green Reference wire is connected to the Signal coaxial outer conductor close to
the Signal connection. This ensures that the Signal and Return currents are equal and
opposite through the common-mode choke (i.e., IRETURN = -ISIGNAL).
•The black Shield wire connects to the same in-circuit location as the Reference wire,
and then electrically connects to the tip at the internal shield of the transmitter. The
current flowing through the Shield wire will drive the reference voltage for the single-
ended amplifier, including the effects of any parasitic capacitance.
The HVFO103, by design, is not a differential probe, so the Signal and Reference wires are
imbalanced in impedance. By using separate Reference (signal return) and Shield wires to carry
currents, the probe segregates these currents to overcome any impact of impedance imbalance
between the Signal and Reference wires. If only the Signal and Reference wires were connected
(and not the Shield wire), the probe response at DC and high frequency would be unaffected, but

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the CMRR would be degraded. If only the Signal and Shield wires were connected (and not the
Reference wire), the probe response at DC would be unaffected, but the high-frequency
response would be degraded, and CMRR may also be degraded.
CAUTION: The Reference and the Shield wires are electrically connected inside the tip.
Failure to connect them to the same measurement potential will damage the DUT and/or
HVFO103.
The common-mode capacitance (CPAR in the drawing) is ~7 pF. This value is highly dependent
on the probe position, and could be larger if the transmitter is positioned close to the DUT
ground. Note that the HVFO uses a dual-reference lead (as described earlier) that separates the
common-mode current from the signal return current. This greatly reduces the effect of the
ground current due to the common-mode capacitance and results in CMRR performance that is
much better than would otherwise be expected for an ~7 pF common-mode capacitance.
Compatibility
The HVFO103 probe is compatible with a wide range of Teledyne LeCroy oscilloscopes equipped
with the ProBus interface. Visit teledynelecroy.com/oscilloscope to confirm compatibility with
your oscilloscope model.
In general, Teledyne LeCroy 12-bit High Resolution Oscilloscopes (HRO) and High Definition
Oscilloscopes (HDO) provide the most offset capability over the widest range of V/div settings
(see p.21 for maximum offset calculations).
Note: HVFO103 is not compatible with WaveSurfer Xs oscilloscopes, which only run up to 32-bit
XstreamDSO 7.2.0.5. Contact Service for available oscilloscope upgrades.
Required Firmware Versions
The 10X tip requires a more recent version of firmware than do the others.
64-bit MAUI oscilloscope
8.3.x.x or higher
64-bit MAUI oscilloscope with 10x Tip
8.7.0.5 or higher
32-bit MAUI oscilloscope
8.1.2.x or higher
32-bit MAUI oscilloscope with 10x Tip
N/A

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HVFO Probe System
HVFO103
The parts shown below are delivered standard with the HVFO103 in a soft carrying case.
The amplifier/modulating transmitter is a
frequency modulating optical transmitter
integrated with a high-performance electrical
amplifier. The transmitter is battery-
powered, so there is no direct connection
from the floating DUT, providing HV isolation
between the device under test (DUT) and the
grounded oscilloscope. It is recharged
through the same USB Micro-B interface
used to connect the tip. A spare transmitter
may be purchased separately so that one
can be charged while the other is in use.
The VersaLink (V-pin) 400/430um fiber optic
cable assembly has low loss and excellent
transmission characteristics, helping to
optimize the battery life of the transmitter. If the attenuation in the fiber optic cable is too high,
or the cable is damaged and not transmitting properly, the probe will provide a warning to the
user. A 1-meter cable is supplied; 2- or 6-meter cables are available as optional accessories. The
cable utilizes an Avago VersaLink connector, enabling it to be interchanged with low cost, off-
the-shelf fiber optic cables. Cables longer than 6 meters may be sourced directly from the
manufacturer (Industrial Fiber Optics, http://www.i-fiberoptics.com/). Satisfactory optical
transmission has been tested using cables up to 25 meters (longer lengths may work as well).
The demodulating receiver utilizes the ProBus interface to communicate tip attenuation value
and proper voltage scaling to the oscilloscope. With the ProBus interface, the HVFO probe
becomes an integral part of the measuring instrument. Power is provided to the receiver
through the signal interface, so there is no need for a separate power supply or batteries.
Also included are a USB-A – USB Micro-B cable and E-Z Micro-Grippers (1 set of 3).

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Attenuating Tips (one required)
Attenuating tips are sold separately from the probe itself, but at least one tip is required for
proper functioning. Tips can be stored in a compartment in the soft carrying case.
Description
Part Number
Quantity
1x (+/-1 V) attenuating tip
HVFO100-1X-TIP-U
1
5x (+/-5 V) attenuating tip
HVFO100-5X-TIP-U
1
10x (+/-10 V) attenuating tip
HVFO100-10X-TIP-U
1
20x (+/-20 V) attenuating tip
HVFO100-20X-TIP-U
1
40x (+/-40 V) attenuating tip
HVFO100-40X-TIP-U
1
The attenuating tip makes a three-wire connection to the DUT, while
the other end of the tip connects to the USB Micro-B input on the
transmitter. Each tip communicates identifying information to the
transmitter. The fixed attenuation determines the maximum voltage
level that can be measured. All tips are interchangeable with any
HVFO transmitter and do not require specialized calibration with a
specific HVFO probe. The E-Z Micro-Grippers may be used with any of
the tips.
Note: Tip selection is important to optimize for best noise performance. Using a tip with a wider
dynamic voltage range than necessary will result in more noise.
Optional Accessories
These items may be purchased separately as accessories to the probe.
Description
Part Number
Quantity
Additional 1-meter fiber optic cable HVFO-1M-FIBER 1
2-meter fiber optic cable HVFO-2M-FIBER 1
6-meter fiber optic cable HVFO-6M-FIBER 1
Additional Amplifier/Modulating Transmitter HVFO10x-XMITTER 1
Optional 1-meter, 2-meter, and 6-meter fiber optic cables

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HVFO103 Probe Specifications
For the current specifications, see the product datasheet at teledynelecroy.com. Specifications
are subject to change without notice.
Specifications
Bandwidth (typical, probe+oscilloscope)
60 MHz
Risetime 10-90% (typical)
7.5 ns
DC Gain Accuracy (warranted)
+/- 2 %
CMRR (typical, 1x tip attached)
140 dB @ 100 Hz
120
dB @ 100 Hz - 1 MHz
85 dB @ 1 - 10 MHz
60 dB @ 10 – 60 MHz
Electrical Characteristics
Input Dynamic Voltage Range
1x tip
5x tip
10x tip
20x tip
40x tip
+/
- 1 V
+/
- 5 V
+/
- 10 V
+/
- 20 V
+/- 40 V
Max. Common Mode Voltage
(from either input to ground)
+/- 35 kV (DC + peak AC)
Max. Input Voltage to Earth
(from either input to ground)
+/- 35 kV (DC + peak AC)
Max. Safe Input Voltage
30 V
RMS
/ 60 V
DC
(hand-held)
Max. Non-destruct Voltage
Lower of 5X dynamic range
or 100 V
Noise (probe only)
1x tip
5x tip
10x tip
20x tip
40x tip
7 mVrms
35 mVrms
70 mVrms
140 mVrms
280 mVrms
WARNING: The probe is not intended for hand-held use above 60 VDC. Always maintain
adequate spacing between floating probe components and earth ground when
measuring at high voltage in a stationary test setup.

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Vertical Sensitivity
1x tip
5x tip
10x tip
20x tip
40x tip
50 mV/div – 1 V/div
2
50 mV/div – 5 V/div
5
00 mV/div – 10 V/div
1 V/div – 20 V/div
2 V/div – 40 V/div
Amplifier/Modulating Transmitter Battery
Charging Interface
USB Micro-B
Typical Life
> 6 hours
Recharge Time
Oscilloscope USB port
USB charger
3 hours
1.5 hours
Cycle Life
> 500 cycles*
* For battery life > 5.5 hours.
Dimensions
Amplifier/Modulating Transmitter
Width
48 mm (1.89 in.)
Length
Body only
With leads attached
90.2 mm (3.55 in.)
245 mm (9.65 in.)
Height
Without feet
With feet
25 mm (0.98 in.)
27.5 mm (1.08 in.)
Attenuating Tips
Insulated Socket Diameter
3 mm (0.12 in.)
Length Green REF Wire
8 cm (3.15 in.)
Overall Length
16 cm (6.3 in.)
Demodulating Receiver
Width
39 mm (1.54 in.)
Length
95.9 mm (3.77 in.)
Height
23.6 mm (0.93 in.)

HVFO103 High-Voltage Fiber Optically Isolated Probe
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Bandwidth
Typical bandwidth of the HVFO103 using any attenuating tip is shown below: