Tektronix P6458 User manual

010-6458-01
lektronOO
COMMITTED TO EXCELLENCE
Instructions
P6458
P6458 ACQUISITION CONTROL PROBE
3619-1
DESCRIPTION
The P6458 Acquisition Control Probe is a 4-channel active probe for use with the SA 501 Signature
Analyzer. The P6458 contains a hybrid integrated circuit that has four FET ampllifiers with differential EGL
outputs. All input channels of the hybrid circuits are protected from damage by static discharges. The high
input resistance and low input capacitance of the probe allows the circuit under test to perform close to
normal operating conditions, with minimal loading.
Probe input threshold levels are established by a voltage source supplied by the test instrument. The
P6458 outputs are compatible with test instruments having differential EGL receivers (e.g., types 10115 or
10216) with 100
Q
differential-input termination. DC power for operating the probe circuitry is derived from
the associated instrument via the probe connector. The broad input range of the P6458 permits its use with
a wide variety of input signal levels.
This instrument is listed with Underwriters Laboratories, Inc., under UL Standard 1244 (Electrical and
Electronic Measuring and Test Equipment).
A Tektronix Lead Set (seeStandard Accessories) is provided with the probe and standard accessories
package. The five input leads (four signals plus one common ground connector) are each 9 inches long and
are molded into a common plug-in connector that plugs into the probe body. Fivemicrocircuit test probe tips
are supplied with the input lead set to provide a convenient means of attaching the inputs to the circuitry
under test. The individual signal leads are each color-coded to permit easy identification when making
connections.
Copyright© 1981, Tektronix, Inc.
070-3619-00
All rights reserved.
APRIL 1981

P6458 Acquisition Control Probe
2
SPECIFICATION
Electrical Characteristics
Characteristics Information
Input Resistance 1 Mn, ±50 kn.
Input Capacitance 5 pF, ± 1 pF (without input leads).
Maximum Input Threshold Control Voltage -16.25 V to +3.25 V with Hybrid powered from -5 V.
-10 V to + 10 V with Hybrid powered from + 5 V.
Maximum Dynamic Input Voltage -40 V to a maximum of 10 V above input threshold level.
-40 V to a maximum of 30 V above input threshold levelfor
RS 232 signals only.
Maximum Nondestructive Voltage to Input 40 V (de + peak ac).
Delay Time
Power Requirements
Voltage
Current
Temperature
Storage
Operating
Altitude
Storage
Operating
Characteristics
Characteristics
Weight (Probe Only)
Length
Probe Head and Cable
Input Lead Set (10-wide)
17 ns ± 2 ns with ± 1 V input signal and threshold at
O
V.
4.7 V to 5.3 V.
140 mA or less at 5 V.
Environmental Characteristics
-55°C to + 75°C.
0°C to +50"C.
To 50,000 feet.
To
15,000 feet.
Physical Characteristics
Information
Information
204 grams (7.1 ounces).
2 meters (6.5 feet).
25 centimeters (9.8 inches).
@

@
P6458 Acquisition Control Probe
OPERATING CONSIDERATIONS
Use of the P6458 as part of a logic analysis system is covered in the associated logic analyzer
instruction manual. The instructions in this section relate mainly to the various means of connecting the
P6458 into the circuitry under test.
Probe Cable Connector
The miniature 25-pin connector at the end of the probe cable should be carefully inserted into one of
the associated test instrument connectors.
Make sure that the probe cable connector is correctly aligned with the test instrument connec-
tor. Damage to the terminals can result from forcing one connector into another.
Probe Input
leads
The five probe input leads, individually color coded for easy identification of channels, are molded into
a common-connector at the output end (see Figure 1).To connect this assembly to the probe head, carefully
push the 5-terminal plug into the socket on the probe head. Be sure the correct sides of the probe head and
plug assembly are facing upward as illustrated. To remove the input-lead set, hold the probe head and pull
the assembly plug straight out away from the probe head.
To minimize the pickup of electromagnetic interference, input leads should be kept as short as possi-
ble. However, to avoid adding errors to critical timing measurements, input leads should all be the same
length.
Input Lead Color Coding
The probe input leads are color-coded as follows:
Channel Color
Ground White
0 Black
Brown
2 Red
3 Orange
3

P6458 Acquisition Control Probe
4
SMALL
ROUND HOLES
Figure 1. Installation of 5-wide input lead set.
Connecting Probe Input Leads to Circuitry
3619-2
A set of five plug-on microcircuit-test probe tips is supplied as a standard accessory to the P6458. The
probe tips can be attached to the test leads by pushing the lead end onto the recessed round pin near the
butt end of the probe tip (see Figure 2). Make sure that the round pin on the probe tip and the connector on
the end of the test lead are properly aligned to prevent damage.
To avoid damage to the probe, do not connect the ground lead to a voltage source above or
below ground reference.
Each probe tip has a retractable hook that grasps a lead, wire, or connector firmly (see Figure 3). To
use the retractable probe tip, push in the base of the probe tip until the hook appears (see Figure 4). Slip the
hook over a lead or connector and release the tip base. The hook will retract and grip the connection firmly.
@

-
@
INPUT TEST LEAD
CONNECTOR
\
Figure 2. Connection of input lead to probe tip.
TIP COMES
OUT
PUSH IN
WITH THUMB
P6458 Acquisition Control Probe
2515-5 2515-6
Figure 3. Attaching the retractable hook tip.
2515-7
Figure 4. Operation of retractable hook tip.
5

P6458 Acquisition Control Probe
Where several probe tips are to be connected close together in a compact area, the probe tips can be
attached vertically onto 0.020 to 0.034 inch round pin connectors or 0.025 inch square pins. Open the hook
by pressing the base of the probe tip and then slide the tip end down onto -theround or square pin (see
Figure 5).
Where space is even more restricted for making connections, pull the test lead out of the retractable
hook tip and slide the connector end of the test lead down onto the round or square pin (the lead connector
also fits onto 0.025 inch square pins and round pins from 0.020 to 0.034 inch). See Figure 6.
2515-8 2515-9
Figure 5. Attaching the hook tip vertically onto a pin connector. Figure 6. Attaching an input test lead connector onto a pio
connector.
6 @

@
P6458 Acquisition Control Probe
MAINTENANCE
The following servicing instructions are for use by qualified personnel only. To avoid personal
injury, do not perform any servicing other than that contained in the operating instructions
unless you are qualified to do
so.
The P6458 Probe is designed to withstand normal operation and handling. However, if the probe fails
or is damaged, replacement parts are available. See the Replacement Parts List for descriptions and part
numbers.
Cleaning
Dirt that accumulates on the probe head can be removed with a soft cloth dampened in a mild
detergent and water solution. Abrasive cleaners should not be used.
Avoid the use of chemical cleaning agents which might damage the plastics used in this instru-
ment. In particular, avoid chemicals which contain benzene, toluene, xylene, acetone or similar
solvents.
Recommended cleaning agents are isopropyl alcohol (lsopropanol) or ethyl alcohol (Fotocol or
Ethanol).
Contaminated contact areas of the connectors, hybrids, and circuit board can be cleaned with a
cotton-tipped applicator dipped in a recommended cleaning agent (above).
Probe Head Component Access
Do not remove hybrid frames
1. Remove the four corner screws and nuts which hold the probe halves together.
2. While pulling the probe body halves apart, note which half covers which side of the circuit board.
See Figure 7 for component locations on the circuit board; and see Figure 8 for probe head cable
connections.
1

P6458 Acquisition Control Probe
8
®
• •
U10
•
U14
OPPOSITE SIDE
PIN 1
.,f-•
if G
0
~
®~E!l
®o
0
EB®
ffi EB
G
0
@EB
0
0 •ego
.,' -@
~
~
@ CH 0, 2, 3, 4*
EB
EI:
*THRESHOLD CONTROL
VOLTAGE INPUTS
Figure 7. Component locations on the circuit board.
3. Replace any detective components.
4. When reinstalling the circuit board in probe body, be sure that the body halt with channel identifica-
tion label covers the circuit board side with the channel input pins.
5. Replace the tour screws that hold the probe body halves together.
Troubleshooting
Equipment Required
• Test Oscilloscope
• Function Generator
• Power Supply
The following information is provided to aid in troubleshooting the P6458. Troubleshooting information
contained in the associated test-instrument instruction manual should be used with the following information
in locating malfunctions.
3619-3
@

@
P6458 Acquisition Control Probe
•
·~ 0
Figure 8. Probe head cable connections.
+
C
TWISTED
-fl-
PAIRS
CABLE
TO P10
GROUNDED
SHIELD
1. Isolate Trouble to a Circuit. To determine if the trouble is in the probe or the test instrument, use
the troubleshooting information in the instruction manual for the test equipment. If the probe is found to be
defective, proceed with step 2.
2.
Visual Check. Remove the two halves of the probe body (refer to the Probe Head Component
Access procedure, above). Check the probe for visible indications of a defect. Look for broken wires,
damaged circuit board, damaged components, etc. Repair or replace any such defective parts. If there are
no visible indications of a defect, proceed with step 3.
3. Check Supply Voltage. The supply voltage to the P6458 can have various values depending upon
the voltage level used in the test instrument. Refer to the probe schematic and the test equipment instrument
instruction manual for the supply voltage assigned to the probe.
If all the channels are affected by the trouble, check supply Voltages, VCC, VDD, and VEE. If one or
more of the channels are operating correctly, proceed with step 4.
NOTE
Supply voltages are measured with respect to the test instrument chassis ground.
3619-4
9

P6458 Acquisition Control Probe
10
+VCC = Chassis Ground - VEE = Chassis Ground
Typical Voltage
+vcc = ov
+voo = -0.5v
-VEE= -5V
Typical Voltage
+vcc = +5V
+voo = +4.5V
-VEE= OV
a. If VCC does not have its assigned voltage, check the VCC cable wire (red) for continuity. If wire
shows no continuity, proceed to step 5.
b. If VEE does not have its assigned voltage, check the VEE cable wire (violet) for continuity. If wire
shows no continuity, proceed to step 5.
c. If the voltage at VDD is the same as VEE, check diode CR4 for an open. If the diode is open,
replace it.
d.. If the voltage at VDD is the same as VCC, check diode CR4 for a short. If the diode is shorted,
replace it.
4. Check Hybrid Operation. If the supply voltages are correct, check for a defective channel on one
of the hybrids.
a. Set the input threshold level of the test instrument to zero volts.
b. Connect a signal lead from a channel input on the probe to a 1 kHz square wave of +1 volt
to -1 volt (use a function generator).
c. With a test oscilloscope, check the + (plus) output (noninverting) and - (minus) output
(inverting) at the cableconnector and at the circuit board for the correct output waveform (see Figure9
for typical waveforms).
See Figure 8 for cable connections at the circuit board; and Figure 10 for output connector
assignments.
d. If an output sig"81is present on the circuit board, but not at the cable connector, check the
cable wire for continuity.
e. If there is no signal at any of the circuit board connections, suspect the hybrid. If the hybrid is
found to be defective, proceed to step 5.
@