Agilent Technologies 1156A User manual

A
User’s Guide
Publication number 01156-97002
September 2005
For Safety and Regulatory information, see the pages at the back of this guide.
© Copyright Agilent Technologies 2001-2002, 2005
All Rights Reserved.
1156A 1.5 GHz Active Probe
99 Washington Street
Melrose, MA 02176
Phone [phone]
Toll Free 1-800-517-8431
Visit us at www.TestEquipmentDepot.com
Back to the Agilent 1156a Product Info Page

2
In This Book
This guide provides user and service information for the 1156A 1.5 GHz Active
Probe.
Chapter 1 gives you general information such as inspection, cleaning,
accessories supplied, and specifications and characteristics of the probe.
Chapter 2 shows you how to operate the probe and gives you information about
some important aspects of probing and how to get the best results with your
probe.
Chapter 3 provides service information.

Contents
3
1General Information
To inspect the probe 7
Accessories Supplied 8
Replaceable Parts and Additional Accessories 10
Characteristics and Specifications 11
General Characteristics 12
To use the probe 14
Probe handling considerations 14
Cleaning the probe 14
Using Probe Accessories 15
To connect the probe 16
2Operating the Probe
110 Ohm Resistive Signal Pin (Green) and Solderable Ground
Socket 21
130 Ohm Resistive Signal Pin (Orange) and Ground Blade
Assembly 25
5 cm Resistive Signal Leads and Solderable SMT or Solderable
Through-hole Ground Pin 29
Socket-end 10 cm Resistive Signal Lead and Solderable SMT or
Solderable Through-hole Ground Pin 33
Micro Clip 37
Undamped Accessories 37
3Service
Service Strategy 42
To return the probe to Agilent Technologies for service 43
Troubleshooting 44
Failure Symptoms 44
Probe Calibration Fails 44
Incorrect High Frequency Response 44
Incorrect Low Frequency Response (pulse flatness) 45
Incorrect Input Resistance 45
Incorrect Offset 45
Offset Will Not Zero 45
Verifying probe input resistance 46
!

6
1156A 1.5 GHz Active Probe
The 1156A 1.5 GHz Active Probe is a probe solution for high-frequency
applications. This probe is compatible with the AutoProbe Interface
which completely configures the Infiniium series of oscilloscopes for the
probe.
General Information

7
General Information
To inspect the probe
To inspect the probe
❏Inspect the shipping container for damage.
Keep a damaged shipping container or cushioning material until the contents of
the shipment have been checked for completeness and the instrument has been
checked mechanically and electrically.
❏Check the accessories.
Accessories supplied with the instrument are listed in "Accessories Supplied" in
table 1-1 later in this chapter.
• If the contents are incomplete or damaged notify your Agilent Technologies
Sales Office.
❏Inspect the probe.
• If there is mechanical damage or defect, or if the probe does not operate
properly or pass calibration tests, notify your Agilent Technologies Sales
Office.
• If the shipping container is damaged, or the cushioning materials show signs
of stress, notify the carrier as well as your Agilent Technologies Sales Office.
Keep the shipping materials for the carrier’s inspection. The Agilent
Technologies Office will arrange for repair or replacement at Agilent
Technologies’ option without waiting for claim settlement.
Figure 1-1
1156A Active Probe
01158e03.cdr
5 Accessory Vials
Accessories
Container
Included with
the probe is an
accessories
container and 5
accessory
vials. All the
included
accessories
are shown in
figure 1-2.

8
General Information
Accessories Supplied
Accessories Supplied
The following figure and table show the accessories supplied with the 1156A
Active Probe.
Figure 1-2

9
General Information
Accessories Supplied
Table 1-1
Accessories Supplied
Item Description Qty Agilent Part Number
1s 130 Ωresistive signal pin (orange) 12 01156-27616
2s Solderable-tip 5 cm resistive signal lead 2 01156-82106
3s Socket-end 5 cm resistive signal lead 2 01156-82105
4s Socket-end 10 cm resistive signal lead 2 01156-82108
5sg Micro clip 25063-2180
1g Ground blade assembly 12 01156-23701
2g Solderable SMT ground pin 12 1253-5054
3g Solderable through-hole ground pin 12 1252-7150
4g Offset ground pin 12 01156-27606
5g Solderable-tip 5 cm ground lead 2 01156-82107
6g Socket-end 5 cm ground lead 2 01156-82103
7g Socket-end 5 cm, 90° pin ground lead 2 01156-82104

10
General Information
Replaceable Parts and Additional Accessories
Replaceable Parts and Additional Accessories
Table 1-2
Replaceable Parts and Additional Accessories
Agilent Part Number Description Qty
E2638A Solderable-tip 5 cm resistive signal lead
Solderable-tip 5 cm ground lead
10
3
E2639A Micro clip 4
E2640A 130 Ωresistive signal pin (orange) 8
E2641A Ground blade assembly 8
E2637A Precision Measurement Kit
includes 2 solderable ground sockets and 2
110 Ωresistive signal pins (green)
1
E2654A EZ-Probe®positioner 1

11
General Information
Characteristics and Specifications
Characteristics and Specifications
The following characteristics are typical for the active probe.
Table 1-3
Characteristics
1 Denotes warranted specifications, all others are typical.
2 For waveforms with edges > 3 ns, the dynamic range is > 12.0 Vpeak-to-peak
3 Installation category (overvoltage category) I: Signal level, special equipment, or parts of
equipment, telecommunication, electronic, etc., with smaller transient overvoltages than
installation category (overvoltage category) II.
Bandwidth1(-3 dB) > 1.5 GHz
System bandwidth (-3 dB) 1156A with 54832B/D or 54835A scope: 1 GHz
Rise and Fall Time (10% to 90%) < 233 ps calculated from
Input Capacitance 0.8 pF
Input Resistance1100 kΩ \1%
Flatness, Swept Response 0.2 dB, 100 kHz to 100 MHz
0.4 dB, 100 MHz to 1.5 GHz
Flatness, Step Response 15% overshoot, 35 ps input edge
10% overshoot: 75 ps input edge; 2%: 1 ns after edge
Dynamic Range2> 5.0 V peak-to-peak
DC Attenuation 10:1
Offset error referred to input <\30 mV
Offset Range ±15.0 V
Offset Gain Accuracy <\3% of setting
Noise referred to input 3.0 mVrms
Propagation Delay 5.5 ns
Maximum Input Voltage340 V peak, CAT I
ESD Tolerance > 5 kV from 100 pF, 300 ΩHBM
Temperature Drift Offset: < 1.0 mV/°C
Attenuation: < 0.1 %/°C
tr
0.35
Bandwidth
-----------------------------=
!

12
General Information
General Characteristics
General Characteristics
The following general characteristics apply to the active probe.
Table 1-4
General Characteristics
Environmental Conditions
Operating Non-operating
Temperature 0 °C to +55 °C−40 °C to +70 °C
Altitude 4000 meter (13,000 ft)
Humidity up to 95% relative humidity
(non-condensing) at +40 °C
up to 90% relative humidity at +65 °C
Power Requirements +12 Vdc @ 3 mA typical
+5 Vdc @ 35 mA typical
-5 Vdc @ 37 mA typical
0.4 W
(voltages supplied by AutoProbe
Interface)
Weight approximately 0.69 kg
Dimensions Refer to the outline in figure 1-3.
Pollution degree 2 Normally only non-conductive pollution occurs. Occasionally, however, a
temporary conductivity caused by condensation must be expected.
Indoor use

13
General Information
General Characteristics
Figure 1-3
1156A Active Probe Dimensions
5.61 mm
0.221 in.
4.9 mm
0.193 in.
01158e20.cdr
Center of ground socket
Center of signal socket

14
General Information
To use the probe
To use the probe
The Infiniium family of oscilloscopes provides both power and offset
control to the 1156A active probe through the front panel connector.
Probe offset is changed by adjusting the vertical offset control on the
Infiniium oscilloscope. The control should be adjusted to center your
waveform within the 5 volt peak-to-peak (12 volts peak-to-peak for slow
waveforms) dynamic range of the probe.
Probe handling considerations
This probe has been designed to withstand a moderate amount of physical and
electrical stress. However, with an active probe, the technologies necessary to
achieve high performance do not allow the probe to be unbreakable. You should
treat the probe with care. It can be damaged if excessive force is applied to the
probe tip. This damage is considered to be abuse and will void the warranty
when verified by Agilent Technologies service professionals.
• Exercise care to prevent the probe end from receiving mechanical shock.
• Store the probe in a shock-resistant case such as the foam-lined shipping case
which came with the probe.
Cleaning the probe
If the probe requires cleaning, disconnect it from the oscilloscope and clean it
with a soft cloth dampened with a mild soap and water solution. Make sure the
probe is completely dry before reconnecting it to the oscilloscope.

15
General Information
Using Probe Accessories
Using Probe Accessories
Before you can use the 1156A probe you must install the signal and ground
accessories that you want to use. As an example, the following figure shows the
installation of the 130 Ωresistive signal pin (orange) and the ground blade
assembly into the probe.
Figure 1-4
Installing the signal and ground pins
There are several probe accessories that can be attached to the 1156A probe
which can make it easier to probe different types of circuits and circuit
conditions. Each accessory has a different affect on the performance of the
probe, as shown in chapter 2.
Probe signal socket
130 Ωresistive
signal pin (orange)
Probe ground socket
Ground blade assembly

16
General Information
To connect the probe
To connect the probe
1Connect the probe output to the oscilloscope input.
2Calibrate the oscilloscope and probe combination using the Infiniium
probe calibration routine.
When the probe has been calibrated, the dc gain, offset zero, and offset gain
will be calibrated. The degree of accuracy specified at the probe tip is
dependent on the oscilloscope system specifications.

18
Introduction
The Agilent 1156A active probe comes with accessories that place a
resistor as close as possible to the circuit being probed. The purpose of
this resistor is to dampen the resonant circuit created when the probe
tip makes physical contact with the circuit. The resonant circuit is made
from the parasitics of the physical connection between the point being
probed and the internal attenuator of the probe.
All probes suffer from the effects of this resonant circuit at the input of
the probe. However, with lower bandwidth probes the resonant
frequency is much higher than the bandwidth of the probe making this
effect less noticeable.
The bandwidth of the 1156A active probe is higher than the resonant
frequency of the physical connection to the probed circuit, even when
using the smallest possible physical connection. Placing a resistor
between the circuit being probed and the parasitics of the physical
connection isolates the circuit being probed from this resonance. This
allows the response of the probe (Vout/Vin) to be flat across the entire
bandwidth of the probe.
Table 2-1
Suggested Configurations and Characteristics
Each suggested configuration is optimized for flattest response and highest input
impedance. For response, this means that the waveform at the output of the
probe will be as close as possible to the waveform at the input of the probe
without introducing overshoot, ringing, or other unwanted perturbations. For
input impedance, this means that the input impedance is as high as possible
throughout the entire bandwidth of the probe, thus never resonating low due to
It is important to understand that the resistor placed at the point being probed
is part of the probe. The optimum value of this resistor depends on the geometry
of the physical connection to the circuit being probed. The optimum value of
resistance is used in each of the suggested configurations shown in table 2-1.
Configuration Bandwidth Rise time Input C Minimum |Zin|
110 ΩResistive Signal Pin (green) and
Solderable Ground Socket
> 1.5 GHz < 235 ps 0.9 pF 125 Ω
130 ΩResistive Signal Pin (orange) and
Ground Blade
1.7 GHz 205 ps 0.8 pF 165 Ω
5 cm Resistive Signal Leads and
Solderable SMT or Through-hole
Ground Pin
1.4 GHz 250 ps 1.2 pF 230 Ω
Socket-end 10 cm Resistive Signal Lead
and Solderable SMT or Through-hole
Ground Pin
850 MHz 410 ps 1.8 pF 275 Ω
Operating the Probe

19
Operating the Probe
the parasitics of the physical connection. Even when using the socket-end 10
cm resistive signal lead, the response and input impedance of the probe are very
well behaved.
Other signal lead lengths may be used with this probe but a resistance value
needs to be determined from the following figure and a resistor of that value
needs to be placed as close as possible to the point being probed.
Optimum Damping Resistor Value Versus Signal Lead Length
If a resistor is not used, the response of the probe will be very peaked at high
frequencies. This will cause overshoot and ringing to be introduced in the step
response of waveforms with fast rise times. Use of this probe without a resistor
at the point being probed should be limited to measuring only waveforms with
slower rise times.
Length (cm)
Resistance (Ω)

20
Operating the Probe
When simulating circuits that include a load model for the probe, a simplified
model of the probes input impedance can usually be used. The following figure
and table contain the information for the simplified model of the probe. For more
accurate load models, see the following sections.
Simplified probe input impedance model
Table 2-2
Configuration A B
110 ΩResistive Signal Pin (green) and
Solderable Ground Socket
125 Ω0.9 pF
130 ΩResistive Signal Pin (orange) and
Ground Blade
165 Ω0.8 pF
5 cm Resistive Signal Leads and Solderable
SMT or Through-hole Ground Pin
230 Ω1.2 pF
Socket-end 10 cm Resistive Signal Lead
and Solderable SMT or Through-hole
Ground Pin
275 Ω1.8 pF

21
Operating the Probe
110 Ohm Resistive Signal Pin (Green) and Solderable Ground Socket
Hints for connecting the probe to the point
being measured
The suggested connection configurations are listed in order of performance. The
smallest physical connection to the point being probed produces the highest
bandwidth and the largest physical connection produces the lowest bandwidth.
Although bandwidth and rise time degrades with the larger connections, each
configuration is optimized to produce a flat response. None of the suggested
configurations introduce overshoot or ringing into the waveform being
measured.
110 Ohm Resistive Signal Pin (Green) and Solderable
Ground Socket
This configuration produces the best probe performance of > 1.5 GHz or rise
times of < 234 ps. The Ground Socket does not come with your probe but can
be ordered from Agilent Technologies as part number E2637A.
110 Ωresistive signal pin (green) and solderable ground socket
The 1156A probe has an input impedance which varies with frequency. The
following schematic shows the circuit model for the input impedance of the probe
when using the 110 Ωresistive signal pin (green) and solderable ground socket.
The Ground Socket comes with a green-colored 110 Ωresistive signal pin which
should be used only when using the Ground Socket.
Green-colored
resistive signal
pin
Board trace

22
Operating the Probe
110 Ohm Resistive Signal Pin (Green) and Solderable Ground Socket
110 ΩResistive Signal Pin (green) and Solderable Ground Socket Input Impedance Model
Magnitude Plot of Probe Input Impedance Versus Frequency
Frequency
| Impedance |
Measured
125 Ω
Modeled

23
Operating the Probe
110 Ohm Resistive Signal Pin (Green) and Solderable Ground Socket
Graph of Vin to Probe and Vout of Probe with a 25 ΩSource
Vout/Vin Frequency Response
Frequency
Frequency