GB75-1 Peak Atlas DCA Pro Advanced Semiconductor Component Analyser with Graphics Display and PC connectivity Model DCA75 Designed and manufactured with pride in the UK User Guide © Peak Electronic Design Limited 2012 In the interests of development, information in this guide is subject to change without notice - E&OE
Atlas DCA Pro User Guide December 2012 – Rev 1 Want to use it now? We understand that you want to use your Atlas DCA Pro right now. The unit is ready to go and you should have little need to refer to this user guide, but please make sure that you do at least take a look at the notices on page 5. Contents Page Introduction....................................................................................4 Important Considerations ...............................................................
Atlas DCA Pro User Guide December 2012 – Rev 1 Contents (continued) Page PC Software Installation............................................................29 Connecting to your PC for the first time ......................................30 Analysing Semiconductors – PC mode ........................................31 PC mode - Curve Tracing functions.......................................32 PC mode - Exporting your data..............................................33 PC mode - Special functions........
Atlas DCA Pro User Guide December 2012 – Rev 1 Introduction The Peak Atlas DCA Pro is an advanced semiconductor analyser that combines simplicity, ease of use and a range of advanced features. You can use your DCA Pro on its own or in combination with a laptop or desktop PC.
Atlas DCA Pro User Guide December 2012 – Rev 1 Important Considerations Please observe the following guidelines: • • • • • This instrument must NEVER be connected to powered equipment/components or equipment/components with any stored energy (e.g. charged capacitors). Failure to comply with this warning may result in personal injury, damage to the equipment under test, damage to your DCA Pro and invalidation of the manufacturer’s warranty.
Atlas DCA Pro User Guide December 2012 – Rev 1 Analysing Components – Standalone Mode The DCA Pro is designed to analyse discrete, unconnected, unpowered components. This ensures that external connections don’t influence the measured parameters. The three test probes can be connected to the component any way round. If the component has only two terminals, then any pair of the three test probes can be used. The DCA Pro will start component analysis when the on-test button is pressed.
Atlas DCA Pro User Guide December 2012 – Rev 1 If the DCA Pro cannot detect any component between any of the test probes, the following message will be displayed: No component detected. If the component is not a supported component type, a faulty component or a component that is being tested incircuit, the analysis may result in the following message being displayed: Unknown/faulty component. Some components may be faulty due to a shorted junction between a pair of the probes.
Atlas DCA Pro User Guide December 2012 – Rev 1 Diodes The DCA Pro will analyse almost any type of diode. Any pair of the three test clips can be connected to the diode, any way round. If the unit detects a single diode, a message similar to the following will be displayed: In this example, the Cathode (symbol of K) is connected to the Green test clip and the Anode (symbol of A) is connected to the Blue test clip, additionally, the Red test clip is unconnected. Diode junction Green-K Blue-A VF=0.694V at 5.
Atlas DCA Pro User Guide December 2012 – Rev 1 Zener Diodes The DCA Pro supports Zener diodes (and Avalanche diodes). Additionally, the instrument can measure the Zener voltage*. Connect any pair of the 3 test leads to the Zener diode. Zener diode Red-K Blue-A VR=5.094V at 5.00mA Following analysis, the details are displayed. component In this example, a Zener diode with a reverse voltage (Zener voltage) of nearly 5.1V has been detected.
Atlas DCA Pro User Guide December 2012 – Rev 1 Diode Networks The DCA Pro will identify multiple diode junctions between the probes. For three terminal devices such as SOT-23 diode networks, all three test clips must be connected. The instrument will show the results for each diode junction in turn. Firstly, the unit will show that it has found a number of diode junctions: The details for the first diode are then displayed (Diode #1).
Atlas DCA Pro User Guide December 2012 – Rev 1 LEDs An LED (light emitting diode) is really just another type of diode, however, the DCA Pro will determine that an LED or LED network has been detected if the diode’s measured forward voltage drop is larger than 1.5V. This also enables the DCA Pro to intelligently identify bicolour LEDs, both two-lead and three-lead varieties. See the section on bicolour LEDs for more information. For two leaded parts, connect any pair of the 3 test clips to your LED.
Atlas DCA Pro User Guide December 2012 – Rev 1 Bicolour LEDs (2-lead types) Bicolour LEDs are generally available in two main varieties; 2-lead and 3-lead types. This section describes the testing of 2-lead bicolour LEDs. These types are internally connected in inverse parallel (back-to-back). Similar to the diode network analysis, each LED within the bicolour LED is detailed in turn.
Atlas DCA Pro User Guide December 2012 – Rev 1 Bicolour LEDs (3-lead types) 3-lead bicolour LEDs are available in common cathode and common anode varieties. The DCA Pro supports both types. In the same way as the 2-lead bicolour LED analysis, each internal LED is detailed separately on the DCA Pro screen. The type of bicolour LED is shown here, in this example we have a common cathode variety. Bicolour LED (3 lead) Common Cathode #1: LED The details for each internal LED are then shown.
Atlas DCA Pro User Guide December 2012 – Rev 1 Bipolar Junction Transistors (BJTs) Bipolar Junction Transistors are simply “conventional” transistors, although variants of these do exist such as Darlingtons, devices with free-wheeling diodes, resistor shunted types and combinations of these types. All of these variations are automatically identified by the DCA Pro and their schematic symbol display on the screen. Both NPN and PNP types are supported.
Atlas DCA Pro User Guide December 2012 – Rev 1 Current Gain (HFE) DC current gain (HFE) is the ratio of the collector current (less leakage) to the base current for a particular operating condition. The DCA Pro measures HFE at a collector current of nominally 5.0mA and a collector-emitter voltage of between 3V and 9V. HFE = IC -ICleak IB (ICleak= leakage current) IB IC =5.0mA The gain of all transistors can vary considerably with collector current, HFE=167 collector voltage and also temperature.
Atlas DCA Pro User Guide December 2012 – Rev 1 Base-Emitter Voltage Drop The DC characteristics of the base-emitter junction are displayed, both the base-emitter forward voltage drop (VBE) and the base current (IB) used for the measurement. VBE=0.703V at IB=5.00mA IB VBE This example shows an NPN baseemitter voltage (VBE) of 0.703V for a base test current (IB) of 5mA. The forward base-emitter voltage drop can aid in the identification of silicon or germanium devices.
Atlas DCA Pro User Guide December 2012 – Rev 1 Collector Leakage Current The collector current that takes place when no base current is flowing is referred to as Leakage Current. Most modern transistors exhibit extremely low values of leakage current, often less than 1µA, even for very high collector-emitter voltages. IB = 0 IC Leakage VBE=0.270V at IB=5.00mA ICLeak=0.
Atlas DCA Pro User Guide December 2012 – Rev 1 Darlington Transistors If the device is a Darlington transistor (two BJTs connected together), the unit will display a similar message to this: NPN Darlington Red-B Green-E Blue-C HFE=9410 For Darlington devices that do not have internal resistors, the gain (HFE) can be very high as expected.
Atlas DCA Pro User Guide December 2012 – Rev 1 Free Wheeling Diode Some transistors, particularly CRT deflection transistors and many large Darlingtons have a protection diode (“free wheeling diode” or “body diode”) inside their package connected between the collector and emitter. If a free-wheeling diode has been detected, it is shown on the schematic symbol.
Atlas DCA Pro User Guide December 2012 – Rev 1 Faulty or Very Low Gain Transistors Faulty transistors that exhibit very low gain C may cause the DCA Pro to only identify one or more diode junctions within the device. This is B because NPN transistors consist of a structure of junctions that behave like a common anode diode network. PNP transistors can appear to be E common cathode diode networks. The common junction represents the base terminal.
Atlas DCA Pro User Guide December 2012 – Rev 1 Enhancement Mode MOSFETs MOSFET stands for Metal Oxide Semiconductor Field Effect Transistor. Like bipolar transistors, MOSFETs are available in two main types, N-Channel and P-Channel. Most modern MOSFETs are of the Enhancement Mode type, meaning that the bias of the gate-source voltage is always positive (For N-Channel types). The other (rarer) type of MOSFET is the Depletion Mode type which is described in a later section.
Atlas DCA Pro User Guide December 2012 – Rev 1 Depletion Mode MOSFETs The fairly rare Depletion Mode MOSFET is very similar to the conventional Junction FET (JFET) except that the gate terminal is insulated from the other two terminals. The input resistance of these devices can typically be greater than 1000MΩ for negative and positive gate-source voltages. Depletion Mode devices are characterised by the gate-source voltage required to control the drainsource current.
Atlas DCA Pro User Guide December 2012 – Rev 1 Enhancement Mode IGBTs C IGBT is an acronym for Insulated Gate Bipolar Transistor. G It combines the input characteristics of a MOSFET with the output characteristics of a Bipolar Junction Transistor. E IGBTs are available in N or P channel types, enhancement mode or depletion mode and with or without a free-wheeling diode. Generally, their operation is very similar to MOSFETs.
Atlas DCA Pro User Guide December 2012 – Rev 1 Depletion Mode IGBTs C Like MOSFETs, IGBTs are available as enhancement mode and depletion mode types. G E Depletion mode IGBTs are characterised by the fact that current can flow between the collector and emitter when there is zero voltage across the gate-emitter terminals. For an N-Channel depletion mode IGBT, the device can only be turned off fully if the gate terminal is taken more negative with respect to the emitter lead.
Atlas DCA Pro User Guide December 2012 – Rev 1 Junction FETs (JFETs) Junction FETs are conventional Field Effect Transistors. The voltage applied across the gate-source terminals controls current between the drain and source terminals. N-Channel JFETs require a negative voltage on their gate with respect to their source, the more negative the voltage, the less current can flow between the drain and source. Unlike Depletion Mode MOSFETs, JFETs have no insulation layer on the gate.
Atlas DCA Pro User Guide December 2012 – Rev 1 “On” Characteristics The DCA Pro measures the gate-source voltage required to reach the onset of VGS(on)=-1.10V good conduction through the JFET’s at ID=5.00mA drain-source. Good conduction is determined when the drain-source current reaches 5mA. For JFETs that have a lower saturation current than 5mA, the DCA Pro will try to use a lower “on” current. Transconductance While the JFET is conducting, the JFET’s gain (transconductance) is measured.
Atlas DCA Pro User Guide December 2012 – Rev 1 Thyristors (SCRs) and Triacs Sensitive low power thyristors (Silicon Controlled Rectifiers - SCRs) and triacs that require gate currents and holding currents of less than 10mA can be identified and analysed with the DCA Pro. Thyristor terminals are the anode (A), cathode (K) and the gate (G). This example shows that a thyristor has been detected: Thyristor (SCR) Red-G Green-K Blue-A Triac terminals are MT1, MT2 (MT standing for main terminal) and gate.
Atlas DCA Pro User Guide December 2012 – Rev 1 Voltage Regulators Voltage regulators are available in many different types and different packages. The DCA Pro is able to identify many types of regulator, typically regulators with outputs less than 8V, depending on current requirements. Voltage Regulator Red-IN Green-OUT Blue-GND VOUT=5.024V IQ=2.54mA VDO=1.83V When a regulator is identified, its pinout, output voltage, quiescent current consumption and drop-out voltage are displayed.
Atlas DCA Pro User Guide December 2012 – Rev 1 PC Software Installation The DCA Pro can be used in conjunction with a PC running Windows XP or later.* Software is provided on the included USB flash drive. Alternatively, you can download the latest PC software package from: www.peakelec.co.uk/downloads/dcapro.zip Before you install the software, ensure you have sufficient (administrator) rights on your machine. Additionally, ensure your PC meets the following requirements: Windows XP, Vista, 7 or later.
Atlas DCA Pro User Guide December 2012 – Rev 1 Connecting to your PC for the first time After the software has successfully installed, it is time to connect the DCA Pro to your PC. Use the supplied USB cable to connect your instrument to a convenient USB socket on your PC. For best performance, we recommend that you connect directly to a USB socket on your PC rather than via a USB hub. If you do use a hub, please make sure it is a powered hub (500mA at 5V).
Atlas DCA Pro User Guide December 2012 – Rev 1 Analysing Semiconductors – PC Mode When the DCA Pro is connected to the PC and the PC is running the companion software, the instrument can be used from the PC screen or from the instrument itself. Pressing “Test” will initiate a component analysis in just the same way as the standalone mode. or Any test results are automatically passed to the PC software and displayed in a text window.
Atlas DCA Pro User Guide December 2012 – Rev 1 Curve Tracing After a component has been analysed, you can perform further tests on the component, such as curve tracing various component parameters. Curve tracing is best performed after the DCA Pro has correctly identified the component and correctly identified the pinout. Depending on the component type, various curve options will become available from the “Tests” menu. Selecting the desired curve type will take you to a fresh curve tab.
Atlas DCA Pro User Guide December 2012 – Rev 1 Curve Tracing – Export Raw Data After the curve tracing operation has completed, you can copy the raw measurement data into the clipboard ready to be pasted into your spreadsheet program. Pasting the data into a spreadsheet is an ideal way of documenting important test results. Simply right-click on one of the curves and select “Copy all”. All the raw measurement data that created the curves is now in the clipboard.
Atlas DCA Pro User Guide December 2012 – Rev 1 Special Functions Firmware Upgrade From the program’s “DCAPro” menu, select “Check for Updates”. If you are connected to the internet, the program will check for new firmware and new PC Software. If newer firmware is available, you will be asked if you want to program that into your DCA Pro. The programming operation should take no more than a minute or so.
Atlas DCA Pro User Guide December 2012 – Rev 1 Audible Settings Your DCA Pro has a built-in sounder for alerting you to various test results and conditions. Additionally, the sounder produces short tones to reinforce the tactile feedback when pressing buttons. Here is a summary of the various tone types: Condition Power-up. Power-down, including auto-off. Button press. Component detected. Faulty, unknown or no part detected. Tone Type Rising 3 notes. Falling 3 notes. Very short “blip”. Short Low-High.
Atlas DCA Pro User Guide December 2012 – Rev 1 Care of your Atlas DCA Pro Your DCA Pro should provide many years of service if used in accordance with this user guide. Care should be taken not to expose your unit to excessive heat, shock or moisture. Additionally, the battery should be replaced at least every 12 months to reduce the risk of leak damage. Please replace the battery. If a low battery warning message appears, immediate replacement of the battery is required.
Atlas DCA Pro User Guide December 2012 – Rev 1 Self Test Procedure Each time the DCA Pro is powered up, a self test procedure is performed. In addition to a battery voltage test, the unit measures the performance of many internal functions such as the voltage and current sources, amplifiers, analogue to digital converters and test lead multiplexers. If any of these function measurements fall outside tight performance limits, a message will be displayed and the instrument will switch off automatically.
Atlas DCA Pro User Guide December 2012 – Rev 1 Appendix A – Troubleshooting First thing to do: It is important that you ensure you’ve got the latest version of firmware (software that’s inside the DCA Pro instrument) and the latest version of PC software. You can do this by connecting the unit to your PC and selecting the menu “DCAPro” and then click on “Check for Updates”. It is possible that a firmware update and/or a PC software update will resolve your problem.
Atlas DCA Pro User Guide December 2012 – Rev 1 Appendix B – Summary Technical Specifications All values are at 25°C unless otherwise specified. Specifications subject to change.
Atlas DCA Pro User Guide December 2012 – Rev 1 Summary Technical Specifications continued: All values are at 25°C unless otherwise specified. Specifications subject to change.
Atlas DCA Pro User Guide December 2012 – Rev 1 Appendix C – Analysis Test Circuits The DCA Pro analyses components by applying signals to the component under test while in a “test circuit”. The test circuits that the DCA Pro uses to analyse various components are shown below. These test circuits are presented here to assist in your understanding of the test conditions that are possible when testing in standalone mode and in the PC mode (for curve tracing etc).
Atlas DCA Pro User Guide December 2012 – Rev 1 JFET/MOSFET/IGBT Test Circuit It’s important to note that the gate-source voltage can be driven negative by making the source voltage drive higher than the gate voltage drive. When this is done however, there is less voltage available to be across the drain-source nodes and the load resistor. Example shown is for an N-Channel JFET. Polarities are reversed for P-Channel devices.
Atlas DCA Pro User Guide December 2012 – Rev 1 Diode Test Circuit This test circuit is used for testing both the forward and reverse characteristics of diodes. Reverse characteristics are particularly useful for the testing of Zener diodes. For the standalone mode, the voltage is automatically adjusted to obtain a “target” current of 5mA. For Zener diodes that have a breakdown voltage of more than about 9V, the target current of 5mA cannot be obtained.
Atlas DCA Pro User Guide December 2012 – Rev 1 Voltage Regulator Test Circuit The test circuit shown here is used for the analysis of voltage regulators (positive regulators in this example). Note that the range of regulator voltages supported will depend on the quiescent current (IQ). A higher quiescent current will cause more voltage to be dropped across the sense resistor and yield less voltage for the regulator itself.
Atlas DCA Pro User Guide December 2012 – Rev 1 Appendix D – Warranty Information Peak Satisfaction Guarantee If for any reason you are not completely satisfied with your DCA Pro within 14 days of purchase you may return the unit to your distributor. You will receive a refund covering the full purchase price if the unit is returned in perfect condition. Peak Warranty The warranty is valid for 24 months from date of purchase.
Atlas DCA Pro User Guide December 2012 – Rev 1 Appendix E – Disposal Information WEEE (Waste of Electrical and Electronic Equipment), Recycling of Electrical and Electronic Products United Kingdom In 2006 the European Union introduced regulations (WEEE) for the collection and recycling of all waste electrical and electronic equipment. It is no longer permissible to simply throw away electrical and electronic equipment. Instead, these products must enter the recycling process.
