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TrackerPXI user's manual
P/N 21-1354
Rev. B, APRIL 2006
Copyright
2005 Huntron, Inc. All rights reserved.
Huntron, Tracker, ProTrack, Sig Assist and Huntron Access are registered trademarks of Huntron, Inc. All other
names are trademarks or registered trademarks of their respective companies.
This document may not be copied in whole or in part, or otherwise reproduced except as specifically permitted
under U.S. copyright law, without the prior written consent of Huntron, Inc.,
15720 Main Street, Suite#100, Mill Creek, WA, 98012, USA.
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Summary of Contents for Huntron TrackerPXI

  • Page 1 Copyright 2005 Huntron, Inc. All rights reserved. Huntron, Tracker, ProTrack, Sig Assist and Huntron Access are registered trademarks of Huntron, Inc. All other names are trademarks or registered trademarks of their respective companies. This document may not be copied in whole or in part, or otherwise reproduced except as specifically permitted under U.S.
  • Page 2 Thank you for purchasing a Huntron TrackerPXI! Contacting Huntron To obtain information about service, accessories and other products, contact: Huntron Inc. 15720 Main Street, Suite#100 Mill Creek, WA 98012 In North America, call 800-426-9265 or 425-743-3171. Huntron is also accessible by: ♦...
  • Page 3: Table Of Contents

    SECTION 1. INTRODUCTION ........................6 1-1 W PXI ..........................6 HAT IS A RACKER 1.2 S .............................. 9 PECIFICATIONS 1-3 H ......................10 UNTRON ORKSTATION OFTWARE SECTION 2. INSTALLATION ........................13 2-1 W ......................13 HAT YOU NEED TO GET STARTED 2-4 T PXI S .
  • Page 4 (1) year from the date of purchase. Huntron further warrants that the software will perform in substantial conformance with the system specifications of the Huntron TrackerPXI at the time of purchase and for the period of one (1) year thereafter.
  • Page 5 Huntron products, being electronic test equipment, are classified as monitoring and control instruments and are presently exempt from the RoHS directives. Huntron is currently using leaded solder in the construction of our products but we are working for total compliance to RoHS to be completed by July 2006.
  • Page 6: Introduction

    Section 1. Introduction 1-1 What is a TrackerPXI A TrackerPXI is a troubleshooting instrument that fits into a PXI or CompactPCI chassis. This instrument uses a troubleshooting technique called Analog Signature Analysis (ASA) for applying a current limited sine-wave voltage to an un-powered circuit or electronic component. The resulting Current (I) and Voltage (V) characteristic (analog Signature) is then stored and displayed for comparisons to known good signatures of a good circuit card or electronic component.
  • Page 7 You can manually connect the TrackerPXI front panel test terminals directly to the circuit card or component that you are testing. Or you can automate the test process by connecting the TrackerPXI to a Huntron Access Prober which automatically moves a test probe over designated test points on a circuit card.
  • Page 8 Fig. 1. Manual probing of un-powered circuit card using the TrackerPXI. Fig. 2. Automatic probing of circuit card using the TrackerPXI and Huntron Access Prober.
  • Page 9: Specifications

    Dimensions 6.3" W x 3.9" H (16cm W x 10cm H) Warranty 1 year limited Specifications subject to change without notice Supplied Accessories Huntron P/N Description 98-0249 1 pair Huntron Microprobes MP20 98-0043 Test Lead Black 06-5217 User's Manual CD...
  • Page 10: Huntron Workstation Software

    Huntron Workstation 4.0 Software 1-3 Huntron Workstation Software The Huntron Workstation software allows control of the TrackerPXI card and uses Windows-like features to implement the troubleshooting process using ASA techniques. Some examples of screen captures are shown below. Specific software details are covered in the Help file.
  • Page 11 Fig 4. Signature of a failed pin. Green Signature is good. Red is suspect.
  • Page 12 Fig 5. Signatures of all failed pins are displayed with the red (failed) signatures superimposed on the good (green) signatures and are sorted by the worst failures displayed first. The troublesheet for each circuit card can be stored. Huntron Workstation software features. Create custom test routines for low volume manufacturing, repair and rework applications •...
  • Page 13: Section 2. Installation

    4) Your Pentium-based PXI or compactPCI chassis running Windows 2000 or Windows XP. 5) This manual. (TrackerPXI user’s manual) 6) Getting started instructions for setting up a TrackerPXI and a TrackerPXI with a Huntron Access Prober. (These instructions are packaged with the hardware and are repeated in this manual.)
  • Page 14 Remove the filler panel of the slot that you have chosen to install the card. Slide the TrackerPXI card in the selected slot. Caution: Do not force the card into the slot. The card should slide in easily and come to a stop when the card connector is about to make contact with the chassis.
  • Page 15 Card is not fully inserted. Pull upward to engage the lock. TrackerPXI not fully inserted. Card is correctly inserted. Tighten these 2 screws. Tracker PXI card fully inserted and locked into position.
  • Page 16 TrackerPXI and hardware serial numbers. The activation codes are printed on the software CD. The activation codes can be e-mailed to you. If you do not know the activation codes, call Huntron technical support (425-743 3171) and provide the serial numbers for the TrackerPXI and the .
  • Page 17 NOTE: The TrackerPXI is already calibrated at the factory. However, if you are connecting a TrackerPXI to a Prober, you will need to calibrate it as a complete system. If you have connected a TrackerPXI to a Prober, follow the steps below to calibrate the system. 18. TrackerPXI calibration with Prober connection.
  • Page 18: Trackerpxi Signal Connections

    2-4 TrackerPXI Signal connections. The TrackerPXI is a single channel Instrument. The two front panel BNC connectors are the Signal and Common connections for the Huntron Access Prober. The other 2 Banana jacks on the front panel are the Signal and Common connections for a set of Huntron Micro-probes. You can therefore manually probe using the Micro-probes without disconnecting the Access Prober BNC connections.
  • Page 19: Auxiliary (Aux) Connector Description

    Normally Low state. Can be driven to High state via software control for detection by external instrumentation. Pin 5: LINE IN. Normally High state. Can be externally shorted to GND to drive it Low for detection by the TrackerPXI software. Pin 6: TRIG OUT. Similar to LINE OUT. Pin 7: TRIG IN.
  • Page 20 Pin 9: OUT ON. Normally Low state. Automatically driven to High state whenever the output sine wave signals are present at the BNC SIGNAL or Banana SIGNAL connectors. Can be enabled via the TrackerPXI software. Zero crossing ZC 3.5V peak SINE On.
  • Page 21: Testing Passive Components

    ASA troubleshooting is applied. This section will briefly familiarize you with TrackerPXI basic operation and teach you how resistor signatures relate to both test range and the resistance of the circuit under test. After completing this section, you will know how to: •...
  • Page 22 Figure 4-2. TrackerPXI – 50 ohm,10V range. To display the analog signature of a resistor: 1. Select the 50 ohm range by clicking the Resistance dropdown button and selecting 50. 2. Place or clip a test lead on the opposite ends of a resistor and observe the signature.
  • Page 23 Below are four analog signatures of different resistors, 150, 1.5 k, 15 k and 150 k ohms in each of the four pre-set Ranges. Note how the slope or angle of each analog signature changes with each resistor's value. 150 Ω 1.5 kΩ...
  • Page 24 50 Ω. This limit on range parameter be set above 10V because R combinations is a result of the TrackerPXI's STAR feature, it protects components from possible excessive power. In order to set V...
  • Page 25 Select the 50Ω Ω Ω Ω and 10V range. Select the Frequency drop down button and vary the test range frequency F . Observe the resistor signatures in the following figures do not change as F changes. Fs = 20 Hz Fs = 60 Hz Fs = 1 kHz Fs = 5 kHz...
  • Page 26 − the internal resistance increases − the signature becomes more vertical TROUBLESHOOTING APPLICATIONS • The TrackerPXI is a fast and efficient continuity tester, providing real time information. • The TrackerPXI will quickly locate resistor defects, shorts, opens and degradation that other testers cannot find.
  • Page 27 Figure 4-11. Using TrackerPXI To Test A Potentiometer. • The TrackerPXI can be used to adjust a potentiometer in circuit to an approximate operational setting. This application requires a known good board. Adjust each potentiometer on the board under repair to match the settings on a known good operational board.
  • Page 28: Capacitors

    4-2. CAPACITORS With a capacitor connected to the TrackerPXI, the test signal across it responds quite differently than a resistor. The typical analog signature of a capacitor is an elliptical or circular pattern due to the fact that relationship between the test signal's current and voltage are non linear.
  • Page 29 CAUTION The device to be tested must have all power turned off, and have all high voltage capacitors discharged before connecting the TrackerPXI to the device. Do the following to display the analog signature of a capacitor: 1. Select the 50Ω Ω Ω Ω , 10V and 60Hz range...
  • Page 30 THE SIGNATURES OF DIFFERENT CAPACITORS IN LOW RANGE The figure below shows analog signatures for four different value capacitors, 1000 µf, 100 µf, 10 µf and 1µf. The TrackerPXI is in the 50Ω Ω Ω Ω , 10V and 60Hz range. 1000 µF 100 µF...
  • Page 31 ) ON THE SIGNATURE OF A 10 µ µ µ µ F CAPACITOR AFFECT OF FREQUENCY (F = 20 Hz. = 60 Hz. = 500 Hz. = 5 kHz. Figure 4-17. Signatures Of A 10 µF Capacitor At Different Frequencies. 54Ω...
  • Page 32 Figure 4-20. Signatures Of A 1µF Capacitor At Different Internal Resistances. 1.24KΩ Ω Ω Ω , 15V and 60Hz range (MED1 range) As the TrackerPXI's internal resistance R decreased, the capacitor's signature changes from a horizontal elliptical pattern to a vertical elliptical pattern. In ASA, a large internal resistance value results in a capacitor signature that looks similar to an open circuit.
  • Page 33 UNDERSTANDING CAPACITOR ANALOG SIGNATURES Figure 4-21. TrackerPXI Core Circuit Block Diagram With A Capacitor. The TrackerPXI signature display displays as a response to its test signal, an analog signature that represents the relationship between voltage, current and resistance of a component.
  • Page 34 • Changing source resistance R : As the resistance is changed from 1 k Ω to 100 k Ω , the following occurs: − X of the capacitor is not affected − V increases so current decreases proportionately − The elliptical signature becomes increasingly vertical How Tracker Parameter Changes Affect Capacitive Signatures Figure 4-22.
  • Page 35 Table 4-1 shows the TrackerPXI's limits for the minimum and maximum capacitance values it can handle. Table 4-1. TrackerPXI Minimum And Maximum Capacitor Values. = 20 Hz. = 5 kHz 100 k Ω 0.01 µ F - 1 µ F 10 pF - 0.01 µ...
  • Page 36 This can be thought of as a resistance in parallel with the capacitance when observing its analog signature. The following examples show what some capacitor leakage problems may look like in the TrackerPXI signature display. Normal Capacitor Leaky Capacitor Figure 4-23.
  • Page 37 • Capacitors with leakage flaws have their ellipses tilted diagonally due to an internal resistance in parallel with the capacitance. APPLICATIONS • The TrackerPXI can locate defective capacitors in or out of circuit. The ranges cover 10 pF to 20,000 µ F. • When analyzing a capacitor's signature, adjust the TrackerPXI's R...
  • Page 38: Inductors

    4-3. INDUCTORS Inductors, like capacitors, have elliptical analog signatures and respond to TrackerPXI's test signal non-linearly. Also like capacitors, an inductor's reactance (resistance to an AC test signal) is dependent on the test signal's frequency. Because of the way they are constructed using wire which some amount of resistance in it, it is hard to find a pure inductance.
  • Page 39 THE SIGNATURES OF DIFFERENT INDUCTORS IN 50Ω Ω Ω Ω , 10V (LOW range) and 2KHz . The figure below shows analog signatures for four different value inductors, 12,000 µH, 1200 µH, 120 µH and 12 µH in LOW range. 12000 µH 1200 µH 120 µH...
  • Page 40 = 2V V, R = 60 Hz , L = 12,000 µH Note that the signature changes from a horizontal to a vertical position as the TrackerPXI's internal resistance R increases. This means the inductor's resistance can be analyzed by...
  • Page 41 Figure 4-31. TrackerPXI Tracker Core Circuit Block Diagram With An Inductor. The TrackerPXI's block diagram shows an inductor between the test terminals. The current is represented by the vertical axis and is derived as a series current that flows through TrackerPXI’s internal resistance, R...
  • Page 42 • Inductors display elliptical signatures similar to capacitors. Since the inductor also exhibits resistance, due to its construction, the ellipse may be distorted. • As the TrackerPXI test signal’s frequency is increased, the ellipse signature becomes flatter. This response is opposite to that of a capacitor.
  • Page 43 AC cord, the AC noise filter, the fuse, the power switch and the primary winding of the transformer, without removing the cover from the computer. • Another simple test for a speaker or microphone is to apply the TrackerPXI signal in V = 50 Ω , F...
  • Page 44: Electromechanical Switching Components

    A mechanical switch has two states: it is either open or closed. When open, no current can flow; when closed, it acts as a short and allows current to flow. The TrackerPXI I can test the switching function of mechanically activated switches easily. Unlike the DVM that...
  • Page 45 Figure 4-34. TrackerPXI With Probes To A Mechanical Switch - SPST Type.
  • Page 46 A relay is a switch that's activated by an electrical control input. The relay consists of switch contacts, magnets and an electromagnetic coil. The TrackerPXI can test the coil part of the relay by looking at its inductive analog signature.
  • Page 47 2. Connect the black test lead from TrackerPXI’s Common jack to one side the relay coil (normally, the minus lead). 3. Connect the red test lead from TrackerPXI’s Signal jack to the other side of the relay coil (normally, the plus lead).
  • Page 48 = 1 kHz Note the characteristic inductive oval in LOW and MED1 ranges. When applying TrackerPXI’s test signal to the coil, there may be an audible ringing sound generated from the relay under test from the switch contacts being excited.
  • Page 49: Testing Discrete Semiconductors

    SECTION 5 TESTING DISCRETE SEMICONDUCTORS 5-1. DIODES The most basic type of solid state semiconductor component is the diode. Diodes are formed by creating a junction between p-type and n-type semiconductor material. The pn junction gives diodes and semiconductor components polarity characteristics that allow them to conduct current when an external voltage is applied.
  • Page 50 Do the following to display the analog signature of a diode: 1. Select 50Ω Ω Ω Ω , 10V and 60Hz range ( LOW Range). 2. Place or clip the red test lead from the TrackerPXI's Signal jack to anode lead of the diode.
  • Page 51 Figure 5-4. TrackerPXI With Probes To A Diode. = 10 Volts = 3 Volts Figure 5-5. Signature of a 1N914 type Silicon Diode. 50Ω Ω Ω Ω and 60Hz range. The diode signatures are similar to each other. In the 50 Ohm range, the test signal voltage is 10 V .
  • Page 52 AFFECTS OF FREQUENCY (F ) ON THE DIODE SIGNATURE With the 3V , 54 Ω Ω Ω Ω range selected and the test signal frequency of 60 Hz, the signature of the diode is shown on the left figure below. Changing only the test signal frequency to 5 kHz displays the signature on the right.
  • Page 53 AFFECTS OF INTERNAL RESISTANCE (R ) ON THE DIODE SIGNATURE Changing TrackerPXI's internal resistance R moves the vertical knee portion of the diode's analog signature. As R increases, the knee of the signature moves inward toward the origin. R controls the current that's flowing through the diode so the forward diode voltage changes in response to the current change.
  • Page 54 UNDERSTANDING DIODE SIGNATURES Figure 5-8 reviews the TrackerPXI's three range parameters and how they affect the diode signature. How Tracker Parameter Changes affect Diode Signatures Figure 5-8. Range Parameters Changes and Affects On Diode Signatures.
  • Page 55 The signature on the right shows only the capacitor signature because the test signal voltage is below the diode's turn on level. When multiple components are connected together, it's important to realize that the TrackerPXI has the ability to selectively display the signature of a single component.
  • Page 56 The signature on the right shows only the resistor signature because the test signal voltage is below the diode's turn on level. Again, when multiple components are connected together, it's important to realize that the TrackerPXI has the ability to selectively display the signature of a single component.
  • Page 57 DIODE FAILURES Diodes can fail in a number of ways, and each type of failure will cause the signature to change. The defective diodes often appear as open and short signatures. Two other types of flaws are internal resistance and leakage. INTERNAL RESISTANCE FLAW IN A DIODE Figure 5-13.
  • Page 58 INTERNAL LEAKAGE FLAW IN A DIODE Figure 5-15. Defective Diode Model With An Internal Leakage Resistance. 54 Ohm, 10 V (LOW) 1.26 KOhm, 15V (MED1) 27.6 Kohm,20V (MED2) Figure 5-16. Signature Of A Diode With Internal Leakage Flaw. 1N914 Diode With A 10 k Ω Resistor In Parallel. Notice that in LOW range there does not seem to be any problem, but that in both medium ranges, you can see the diode conducting when it should be acting like an open.
  • Page 59 0.6V and the other at the zener voltage of the diode. In ASA terminology, this two knee signature is known as the classic "chair" pattern that is common in many solid state semiconductor components. Figure 5-17. TrackerPXI Core Circuit Block Diagram With A Zener Diode.
  • Page 60 Figure 5-18. Single Zener Diode And 2 Zener Diodes In Series. Single 1N5239B Zener Diode 2 Zener Diodes in Series, 1N5239B Figure 5-19. Signature Of A Single Zener Diode And 2 Zener Diodes In Series. 20V, 27.6 KOhm (MED2) Range Since each horizontal division on the Signature display graticule (in MED2 range) is approximately 5 Volts, from the signature on the left you can estimate that this is about a 9 volt zener diode.
  • Page 61 • The polarity of an unmarked diode can be determined by the orientation of the display with a known diode. • The TrackerPXI can be used to identify an unknown zener diode. If the zener diode is damaged, locate a good one, possibly on another board or in the same circuit and use the TrackerPXI to approximate the voltage.
  • Page 62: Transistors

    5-2. TRANSISTORS A bipolar transistor is a three layer device. There are two basic types. A PNP transistor has a layer of n-type silicon material sandwiched between two layers of p-type material. An NPN transistor has a layer of p-type silicon material sandwiched between two layers of n-type material.
  • Page 63 IMPORTANT NOTE Use of this instrument may alter the current gain (h or ß) of a bipolar transistor whenever the emitter is tested. Either the base-emitter or collector-emitter test circuits satisfy this criterion. While heating of the device due to the current produced by the instrument may cause a temporary change in h (most noticeable in the low range), a permanent shift in h may occur whenever the base-emitter junction is forced into reverse breakdown (~6-20...
  • Page 64 BIPOLAR TRANSISTOR SIGNATURES In order to better understand the signatures that transistors create on the TrackerPXI, we can model these devices in terms of equivalent diode circuits. These are shown in figure 5- 21. These figures show that the collector-based junction analog signature looks similar to a diode signature, and the emitter-base junction signature looks similar to a zener diode signature.
  • Page 65 Do the following to display the analog signatures of a bipolar transistor: 1. Select the 1.26 KOhm, 15V (MED1) range. 2. Place or clip the red test lead from the TrackerPXI's Signal jack to collector lead of the transistor. 3. Place or clip the black test lead from the TrackerPXI's Common jack to base lead of the transistor.
  • Page 66 Diode 1N914 PNP Transistor 2N3906 NPN Transistor PN2222A Figure 5-24. Signature Of A Diode And Collector-Base Of A Transistor. 1.26 KOhm, 15V (MED1) Range Notice that the collector-base signature of a NPN transistor is identical to the signature of diode. The collector-base signature of a PNP transistor, which has opposite polarity from a NPN, looks similar to a diode with its polarity reversed.
  • Page 67 PNP Transistor - 2N3906 NPN Transistor - PN2222A Figure 5-26. Signature Of The Collector-Emitter Of A PNP And NPN Transistor. 1.26 KOhm, 15V (MED1) Range, Emitter To Common. You can see that the collector-emitter signature of a PNP transistor looks like a forward biased diode with the knee at approximately +7 Volts.
  • Page 68 Sometimes, we need to identify unknown transistors. We may need to replace one in a circuit for which we do not have a schematic. The TrackerPXI makes this a relatively simple procedure because each type of junction has a characteristic signature. This makes it possible to identify each of the terminals and the polarity of the transistor.
  • Page 69 Do the following: 1. Probe pin 1 with the red probe and pin 2 with the black probe. 2. Identify the signature. 3. This looks like a collector-base signature. What you do not know yet is which pin is the collector and which pin is the base? Figure 5-28.
  • Page 70 1. Now that you know that pin 2 of the unknown transistor is the collector. Place the black probe to the base on pin 1 and move the red probe to the emitter on pin 3. A base to emitter signature will be displayed. This transistor is a NPN type since the base-emitter signature matches a NPN transistor.
  • Page 71 DARLINGTON BIPOLAR TRANSISTOR SIGNATURES The Darlington transistor is basically two transistors paired together in a special configuration. The emitter of the first transistor is connected to the base of the second transistor. The collectors of both transistors are connected together. The base of the first transistor serves as the external base lead and the emitter of the second transistor serves as the external emitter lead.
  • Page 72 • The TrackerPXI can be used to determine the type of transistor; bipolar, Darlington, FET, etc. • The TrackerPXI can be used to identify the polarity of a transistor (PNP or NPN). • The TrackerPXI can be used to determine the base, collector and emitter on an unknown transistor.
  • Page 73: Solid State Switching Components

    Do the following to display the analog signature of a phototransistor: 1. Select the 1.26 KOhm, 15V (MED1) range 2. Place or clip the red test lead from the TrackerPXI's Signal jack to collector lead of the component. 3. Place or clip the black test lead from the TrackerPXI's Common jack to emitter lead of...
  • Page 74 Figure 5-39. TrackerPXI With Test Probes To A Phototransistor. No Light With Light Figure 5-40. Signatures Of A NPN Phototransistor - MRD3056 Type. 15V, 1.26 KOhm (MED1) range, C-E Junction The phototransistor's signature is similar to a diode's signature in reverse breakdown mode...
  • Page 75 SCRS AND TRIACS A SCR and triac are semiconductor components that are used in switching applications. A SCR (silicon controlled rectifier) is used for DC switching circuits. A triac is used for AC switching circuits. This section will demonstrate how to dynamically test these components. Silicon Controlled Rectifiers (SCR’s) The SCR is a switching semiconductor device that conducts positive current only.
  • Page 76 1. Select the 20V, 27.6 KOhm ( MED2) range with 60 Hz Frequency. 2. The yellow LED will be on next to the MED2 range once activated. 3. Place or clip the red test probe from the TrackerPXI's Signal jack to gate lead (G) of the component.
  • Page 77: Testing Integrated Circuits

    200, although quite often many pins share quite similar signatures. This can make troubleshooting easier by giving us an easy-to-find signature to use as a comparison. In this section, it is important to understand how the TrackerPXI and ASA respond to these circuits. INTEGRATED CIRCUIT FAILURES...
  • Page 78 A functioning IC may stop working for a number of reasons. Some of the most common causes of IC failures are: • EOS Electrical Over Stress. The IC’s maximum electrical specifications have been exceeded. This condition may result in the IC developing internal shorts and opens.
  • Page 79 DIGITAL INTEGRATED CIRCUIT SIGNATURES Before we examine the analog signatures of an IC, let's study the block diagram of a 74LS245 octal bi-directional bus buffer to introduce some basic concepts. This IC is a member of the low power Schottky transistor-transistor logic family (LSTTL). Examine the block diagram for this chip below.
  • Page 80 For this example, the ground pin of the 74LS245 is pin 10. 3. Use the red test lead from the TrackerPXI's Signal jack. Probe each pin of the IC and view its signature on TrackerPXI's signature display. For this example, pins 2 to 9 and 11 to 18 are all buffer circuits so they will have identical signatures.
  • Page 81 COMPARING TWO TTL FAMILIES Although the logic function is the same, there are differences in the circuitry of each logic family. These differences can be readily seen in their signatures using the TrackerPXI. We will illustrate these concepts with the following example of two hex inverters, a 7404 and a 74LS04 from different logic families.
  • Page 82 Pin 1 input - TTL3 range Pin 2 output - TTL3 range Pin 14 power - TTL1 range 20V, 10K Ohm, 200Hz 20V, 10K Ohm, 200Hz 10V, 100 Ohm, (TTL1) Figure 6-5. Signatures Of A 7404 Hex Inverter. Pin 1 input - TTL3 range Pin 2 output - TTL3 range Pin 14 power - TTL1 range 20V, 10K Ohm, 200Hz...
  • Page 83 For this example, the ground pin of the 74HC14 is pin 7. 3. Use the red test lead from the TrackerPXI's Signal jack and probe each pin of the IC. For this example, pins 1, 3, 5, 9, 11, and 13 are all input buffer circuits so they will have identical signatures.
  • Page 84 CMOS COMPONENTS AND TEST SIGNAL FREQUENCY F CMOS logic circuits inherently have a significant amount of internal capacitance. This junction capacitance is visible in the CMOS signatures when using the TrackerPXI. Capacitance in CMOS circuitry may be emphasized or de-emphasized by changing the frequency of the test signal.
  • Page 85 IC or boards ground pin. 3. Place or clip the red test lead from the TrackerPXI's A test terminal to the reference or known good IC's pin. For this example, start with pin 1 of the known good IC.
  • Page 86: Analog Circuits

    ICs.. OP AMPS Frequently, each pin of an op amp creates a different signature on the TrackerPXI. This signature is the result of the internal design of the chip and both the internal and external circuit elements connected to it.
  • Page 87 4 and the positive power supply is pin 8. 3. Use the red test lead from the TrackerPXI's Signal jack and probe each pin of the IC. 4. Observe that the signature of each of the op amp's pins are unique.
  • Page 88 Pin 2 -Input Pin 3 +Input Pin 6 Output Figure 6-15. Signatures of an Op Amp (741 Type) in 10V, 50 Ohm, 60 Hz (LOW) range. Common to Pin 4. Pin 2 -Input Pin 3 +Input Pin 6 Output Figure 6-16. Signatures of an Op Amp (741 Type) in 20V, 27.6K Ohm, 60Hz (MED2) range. Common to Pin 4.
  • Page 89 The op amp has three main terminals; + input, - input and output. An alternative way to perform ASA on the op amp is to connect TrackerPXI's Common terminal to the op amp's output while making a comparison with the red test probe to the “ + ” and then the “ - ” leg.
  • Page 90: Low Voltage

    • Integrated circuits are complex devices that are built using basic electronic components. • The IC signatures resemble zener diodes. • There are many causes for IC failures and the TrackerPXI can display its "health" as resistive leakage, an open or a short.
  • Page 91 LV logic family are different from the conventional HC logic family. The TrackerPXI has the built-in "SMT" test range group which has been optimized for this LV logic. SMT is an abbreviation for surface mount technology and refers to the physical IC package type in which the LV logic family is commonly available.
  • Page 92 For this example, the ground pin of the 74LVQ245 is pin 10. 3. Use the red test lead from the TrackerPXI's Signal jack and probe each pin of the IC. For this example, pins 2 to 9 and 11 to 18 are all buffer circuits so they will have identical signatures.
  • Page 93 • Integrated circuits are complex devices that are built using basic electronic components. • The IC signatures resemble regular and zener diode signatures. • There are many causes for IC failures and the TrackerPXI can display its "health" as resistive leakage, an open or a short.

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