Agilent Technologies 1145A Manual

User and Service Guide
Publication number 01145-92005
May 2014
For Safety, Regulatory, and publishing information, see the pages at the back of
this book.
© Copyright Agilent Technologies Company 2000-2014
All Rights Reserved.
1145A 2-Channel Active Probe

2
Contents
Specifications 4
Characteristics 4
General Characteristics 5
Operating the Probe 6
Probe Power Connection 8
Cleaning the Probe 8
Service Strategy 8
Adjustments 11
Calibration Testing Procedures 15

3
The 1145A 2-Channel Active Probe
The 1145 2-Channel Active Probe is a 10:1 probe with a 750 MHz bandwidth.
The FET amplifier allows a high input resistance and low input capacitance which
minimizes the loading of the circuit under test. The output impedance of the
probe is 50 Ω, which allows the probe cable to be extended with a 50-Ωcoaxial
cable.
The probe can be powered by the probe power outputs of the 54520 and 54540
series oscilloscopes. To use the probe with other instruments, you can use the
1142A power supply.
Accessories Supplied
.
Accessories Available
You can order the following accessories from Agilent Technologies.
• E.F. Johnson socket adapter, Agilent Technologies part number 01145-63201
• Calibration kit, Agilent Technologies part number 01145-68701
1Probe pin, quantity supplied 4, kit #16517-82107
2SMT grabber, quantity supplied 5, kit #16517-82109
3Ground lead pin-socket, quantity supplied 2, kit #16517-82106
4Ground extender, quantity supplied 2, kit #16517-82105
5SMT leads, quantity supplied 2 red and 2 black, kit #16517-82104
You can order additional quantities of the above parts, see page 8 for ordering
information

4
1145A 2-Channel Active Probe
Specifications
Specifications
Bandwidth 1≥750 MHz
Rise Time 1,2 ≤470 ps
Attenuation 310:1 ±3%
Input Resistance 1 MΩ, ±2%
Maximum Input Voltage ±40 V (dc + peak ac)
1. Above 35 °C, bandwidth and risetime degrade approximately 1/2%/°C
2. Rise time figure calculated from tr = 0.35/Bandwidth.
3. When connected to an instrument input of 50 Ω, ±0.5%
Characteristics
Input Capacitance 2 pF (typical)
Overshoot and Ringing Less than ±10% for the first 6 ns, ±4% from 6 ns to
20 µs, ±1.5% thereafter.
Output Voltage Offset Error at output Less than ±1 mV
Input Dynamic Range 0 to ±6.0 V
Output Load Requirement 50Ω
!

5
1145A 2-Channel Active Probe
General Characteristics
General Characteristics
1145A Dimensions
Environmental
Conditions
Operating Non-operating
Temperature 0 C to +55 °C (32 °F to
+131 °F)
-40 °C to +70 °C (-40 °F to +158 °F)
Humidity up to 95% relative humidity
(non- condensing) at +40 °C
(+104 °F)
up to 90% relative humidity at +65°C
(+149 °F)
Altitude up to 4,600 meters
(15,000 ft)
up to 15,300 meters
(50,000 ft)
Vibration Random vibration 5 to 500
Hz, 10 minutes per axis,
0.3grms.
Random vibration 5 to 500 Hz, 10 min.
per axis,
2.41 grms. Resonant search 5 to 500 Hz
swept sine, 1octave/min. sweep rate,
(0.75g), 5 min. resonant dwell at 4
resonances per axis.
Power
Requirements
dc ±6 V to ±3% (at approximately 150 mA each supply)
Weight Net: approximately 8 oz.
Shipping: approximately 1 kg (2.2 lb)
Dimensions Refer to the outline drawing below.

6
1145A 2-Channel Active Probe
Operating the Probe
Operating the Probe
The following information will help you get the most out of your measurement
when operating the probe.
Typical Input Impedance vs. Frequency
!

7
1145A 2-Channel Active Probe
Operating the Probe
Typical System Bandwidth
Typical Rise Time vs. Input Voltage
CAUTION Be sure to limit the input of this probe to voltages within the specified working
voltage. Though the probe is designed with safeguards against static electricity
and noise, the input is sensitive to and may be damaged by excessive voltage.
CAUTION This probe is a delicate device. Dropping it or exposing it to strong vibration
or shock can damage it and cause a malfunction. Please handle it with care.

8
1145A 2-Channel Active Probe
Probe Power Connection
Probe Power Connection
The following drawing shows the input power connections. The power
requirements are given in the General Characteristics.
Cleaning the Probe
Do not use petroleum based solvents to clean the probe. Clean the probe with
a mild soap and water and immediately wipe the probe with a dry cloth.
Service Strategy
If your probe fails during warranty, normal warranty service apply. If the probe
is not under warranty when it fails, you can order any of the following parts from
Agilent Technologies.
Pin 8, -6 V
Pin 3, +6 V
Pin 7, Ground
Shell, Cable Shield
Part Number Description
01145-66501 Loaded Board
01145-61601 Main Cable
01145-60602 Probe tip and cable
16517-82104 SMT lead kit, 4 red and 4 black
16517-82105 Ground extender kit, box of 20
16517-82106 Ground lead pin-socket kit, box of 20
16517-82109 SMT grabber kit, box of 20
16517-82107 Pin probe kit pin, box of 4

9
1145A 2-Channel Active Probe
To replace the main cable
To replace the main cable
Due to the difficulty in soldering the main cable to the printed circuit assembly,
Agilent Technologies recommends that you return the probe to an Agilent
Technologies Service Center if the main cable or printed circuit assembly need
to be replaced. Because there are low temperature solder connections inside the
main cable, make sure you heat sink the main cable before soldering on it.
To replace the probe tip and cable
1Use a Torx 10 screwdriver to remove the four screws holding the
clamshell pod case together.
2Lift off the tip of the clamshell pod case.
3Use a solder iron to unsolder the center conductor wire of the faulty
probe lead from the bonding pas on the printed circuit assembly.
4Because the ground legs plug into small sockets under the cable, use a
pair of needle nose pliers to lift the faulty probe lead away from the
printed circuit assembly.
5Flow enough solder onto the vacant solder pad for a good solder joint.
6Inter the probe ground legs of the new cable into the circuit board pin
sockets.
7While holding the probe ground legs in place, place the notched strain
relief into the slot of the lower half of the clamshell cover.
8Because the wire to the center lead is very fragile, use caution when
soldering it. Resolder the center lead on the vacant solder joint. The
resulting solder joint should be very similar to the other probe lead.
9Inspect the solder joint for good soldering integrity.
10 Check the cable alignments inside of the pod. Replace the top of the
pod, then install the four screws.

10
1145A 2-Channel Active Probe
To return the probe to Agilent Technologies for service
To return the probe to Agilent Technologies for service
Before shipping the instrument to Agilent Technologies, contact your nearest
Agilent Technologies sales office for additional details.
1Write the following information on a tag and attach it to the instrument.
• Name and address of owner
• Instrument model number
• Instrument serial number
• Description of the service required or failure indications
2Remove all accessories from the instrument.
Accessories include all cables. Do not include accessories unless they are
associated with the failure symptoms.
3Protect the instrument by wrapping it in plastic or heavy paper.
Anti-static wrapping or packaging is strongly recommended.
4Pack the instrument in foam or other shock absorbing material and
place it in a strong shipping container.
You can use the original shipping materials or order materials from an Agilent
Technologies Sales Office. If neither are available, place 3 to 4 inches of shock-
absorbing material around the instrument and place it in a box that does not
allow movement during shipping.
5Seal the shipping container securely.
6Mark the shipping container as FRAGILE.
In any correspondence, refer to instrument by model number and full serial
number.

11
1145A 2-Channel Active Probe
Adjustments
Adjustments
There is no defined adjustment interval for the active probe. The adjustments
are done at Agilent Technologies and does not require periodic maintenance. You
should only make adjustments when replacing the probe tip and cable assembly,
the printed circuit board assembly, or as you think is needed based on your past
experience.
The equipment required for the adjustments is listed below. Any equipment
satisfying the critical specifications listed may be substituted for the
recommended model.
Allow the probe to warm up for at least 15 minutes prior to beginning
adjustments.
Equipment Required
CAUTION The adjustments are easily damaged if you use the wrong tool or any force at
all. Make sure you use the adjustment tools that are part of the calibration kit,
Agilent Technologies part number 01145-68701.
Equipment Critical Specification Recommended
Model/Part
Signal Generator Square wave, rise time <300 ps, OV to 1 Vp,
<5% flatness
8131A/B (or
equivalent)
Oscilloscope >10 GHz bandwidth 54121T (or
equivalent)
Power Supply Power for probe under test Oscilloscope or
1142A
Termination SMA feedthrough, 50Ω0955-0736
Adapter* Type N(m) to SMA (m), 50Ω1250-1994 (or
equivalent)
Adapter* SMA(f)-to-probe 16517-27601
Adapter SMA (m) to BNC (f) 1250-1200
Adapter SMA (f-f) 1250-1158
*Part of calibration kit, Agilent Technologies part number 01145-68701.

12
1145A 2-Channel Active Probe
Adjustments
1Connect the equipment as shown below with the following front-panel
settings.
Equipment setup
8131A/B 54121T Trigger
Mode Auto Time base Slope Pos
Period 50 ms Time/div 5ms/div HF sense Off
Delay 0Delay Min HF Reject Off
Width/DS$C 50% Sweep Trg’d Trigger level -260 mV
High 1 V Channels Display Mode
Low 0 V Channels 1, 2, 4 Off Average 1
Offset 0.5 V Channel 3 On Screen Single
Outputs Enabled Volts/div 20 mV/div Graticule Grid
Offset 50 mV Bandwidth 12.4 GHz

13
1145A 2-Channel Active Probe
Adjustments
2If you installed a new board or cable assembly, set all the adjustments
(expect COMP) to the clockwise position. If you are tweaking the
adjustments, you can set them to the clockwise position or leave them
where they were last set.
3Adjust GAIN for a flat pulse.
If you turn on the DeltaV marker, you can use it as a reference for a flat line.
4Change the pulse generator to 50-µs period and change the scope to
5 µs/div.
5Adjust COMP for flat pulse.
Again, you can use the DeltaV marker as a reference for a flat line.
6Change the pulse generator to a 50-ns period and change the scope to
1 ns/div. Adjust the scope’s delay to position the pulse edge 2.5 ns from
the left hand edge of the screen.

14
1145A 2-Channel Active Probe
Adjustments
7Adjust RA for a flat pulse top.
8Adjust RB for a linear rising edge.
9Adjust DAMP for about 6% overshoot.
10 Temporarily place the cover on top of the probe body, then measure the
pulse rise time.
The rise time should be ≤470 ps and overshoot about 9 to 10%. You may need to
remove the cover and make minor adjustments to RA, RB, and DAMP to meet
specifications.
11 Repeat steps 1 though 10 for the other channel.
12 Install the cover, and verify the performance still meets specifications.
About 9 to 10% overshoot and a rise time ≤470 ps.

15
1145A 2-Channel Active Probe
Calibration Testing Procedures
Calibration Testing Procedures
The procedures in this section test the performance of the 1145A active probe
to ensure that it meets its warranted specifications.
Calibrating Testing Interval
The calibration test procedures may be performed for incoming inspection of the
instrument and should be performed periodically thereafter to ensure and
maintain peak performance. The recommended test interval is yearly or every
2,000 hours of operation. The amount of use, environmental conditions, and the
user’s experience concerning need for testing will contribute to verification
requirements.
Equipment Required
The equipment required for the calibration tests is listed at the test. Any
equipment satisfying the critical specifications listed may be substituted for the
recommended model.
CAUTION Allow the probe to warm up for at least 15 minutes prior to beginning calibration
tests. Failure to allow warm-up may cause the probe to fail tests.

16
1145A 2-Channel Active Probe
Input Resistance
Input Resistance
Specification
Equipment Required
1Connect the DMM between the probe tip and the ground at the tip of
the probe.
2Set up the DMM to measure resistance.
DC Gain Accuracy
Specification
Equipment Required
Equipment Critical Specification Recommended
Model/Part
Digital Multimeter Resistance ±1% 34401A
Equipment Critical Specification Recommended
Model/Part
Digital Multimeter Better than 0.1% accuracy at 1 KHz34401A
Power Supply 1 V ±1% 6114A (or equivalent)
Power Supply Power for probe under test Oscilloscope or
1142A
Termination BNC feedthrough, 50Ω±0.5% 11048C
Adapter BNC (f) to banana (m) 1251-2277

17
1145A 2-Channel Active Probe
DC Gain Accuracy
1Using the DMM, set the output of the power supply to 1.0 V ±0.1%.
Power supply voltage ___________.
2Connect the equipment as shown below.
Before you connect the power supply to the probe, you will measure the probes
output offset voltage in step 3.
3Using the DMM, measure the probe’s dc output offset voltage on
channel 1.
Probe output offset voltage ___________.
Typically the offset will be much less than 1 mV.
4Connect the probe’s channel 1 input connector to the power supply.
5Using the DMM, measure the output of the probe.
Probe output voltage ___________.
6Calculate the dc gain.
The dc gain should be between 0.097 and 0.103 (0.10 ±3.0%)
7Repeat steps 1 through 6 for channel 2.
dc Gain Probe output voltage - Probe output offset voltage
Power supply voltage
------------------------------------------------------------------------------------------------------------------------=

18
1145A 2-Channel Active Probe
Bandwidth
Bandwidth
Specification down less than 3dB, dc to 750 MHz
Equipment Required
Equipment Critical Specification Recommended
Model/Part
Signal Generator 50 MHz to 800 MHz 8663A
Power Meters (2) or
one Dual-Channel
50 MHz to 800 MHz
±3% accuracy
436A (2),
437A (2), or
438A (1)
(or equivalent)
Power Sensor (2) 50 MHz to 800 MHz, 300 mW 8482A
Power Splitter Type-N, dc to 800 MHz, ≤0.2 dB tracking 11667A
Power Supply Power for probe under test Oscilloscope or
1142A
Termination SMA feedthrough, 50 Ω0955-0736
Adapter* Type N(m) to SMA(m), 50 Ω1250-1994 (or
equivalent)
Adapter* SMA(f)-to-probe 16517-27601
Adapter BNC(m) to N(f), 50 Ω1250-0077
Adapter N(m-m), 50 Ω1250-0778
*Part of calibration kit part number Agilent Technologies 01145-68701

19
1145A 2-Channel Active Probe
Bandwidth
1Zero and calibrate the power meters with the power sensors.
2Connect the equipment as in the drawing below.
3Connect the probe power input to the oscilloscope or 1142A
4Set the signal generator for 50 MHz at 0.0 dBm.
5Set the power meter calibration factors to the 50 MHz value on the
power sensors.
6Adjust the signal generator power output for exactly -6.0 dBm as read
on the input power meter.
7Note the power level reading on the output power meter.
50 MHz power level _____________ dBm.
8Change the signal generator frequency to 750 MHz.
9Set the power meter calibrating factors to the 750 MHz value on the
power sensors.
10 Relevel the signal generator output power for a -6.0 dBm reading on the
input power meter.
11 Note the power level reading on the output power meter.
750 MHz power level _____________ dBm.
12 Subtract the reading in step 7 from the reading in step 11.
The difference should be ≤3.0 dB.

20
1145A 2-Channel Active Probe
Calibration Test Record
Calibration Test Record
Agilent Technologies 1145A Active Probe
Serial No.:_______________________
Certification Date:_________________
Tested By:_______________________
Recommended Test Interval: 1 Year
Recommended Date of Next Certification:_________
Certification Temperature:_____________________
_______________________________
_______________________________
Test Limits Results
Channel 1 Channel 2
Input Resistance 1.0 MΩ±2%, 980 kΩto 1.020 MΩ__________ __________
dc Gain Accuracy 0.1 ±3%, 0.098 to 1.103 __________ __________
Bandwidth down less than 3 dB at 750 MHz __________ __________