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Peak DCA75 Semiconductor Analyser with Curve Tracing

Featuring USB and a graphics display, this new instrument represents a major advance in handheld semiconductor analysis. 

Datasheet User Guide

The all new DCA Pro - Advanced Semiconductor Analyser with Curve Tracing

See the DCA75 on YouTube

See our DCA75 YouTube video

DCA Pro analysing a TIP110 Darlington
DCA Pro analysing an old germanium OC71
DCA Pro curve tracing of OC71 on a PC
Peak USB Flash Drive with PC software included

Click here for latest software and firmware 

Key Features
  • Automatically identify part type (eg, Transistor, JFET, IGBT, Regulator, Zener, Diodes, etc).
  • Automatically identify pinout (connect any way round).
  • Measure lots of component data.
  • Perform further detailed component analysis with the PC software included on the Peak USB flash drive.
  • Complete with premium gold plated hook probes.
  • Online upgradeable.
  • Single alkaline AAA battery included (not used when connected by USB).
  • 24 month warranty as standard.

The DCA Pro is an advanced new design that features a graphics display, USB communications, PC Software and an enhanced component identification library.

The DCA Pro supports all the components that the popular Peak Atlas DCA55 supports, but adds plenty more.

Components supported and stand-alone measurements include:

  • Transistors (BJTs including Darlingtons and "digital" transistors), Silicon and Germanium types. Measures gain, VBE , collector leakage and collector saturation voltage. Unijunction transistors (UJTs) are not currently supported.
  • MOSFETs, enhancement mode and depletion mode types. Measure on-threshold (at ID=5mA), approx transconductance (for span of 3mA-5mA) and RDS(on) to a resolution of 1Ω.
  • JFETs, including normally off SiC types. Measures pinch-off voltage (at ID=5μA), approx transconductance (for span of 3mA-5mA) and RDS(on) to a resolution of 1Ω.
  • IGBTs (insulated gate bipolar transistors). Measures on-threshold (at IC=5mA),  approx transconductance (for span of 3mA-5mA) and collector saturation voltage.
  • Diodes and Diode networks. Measures forward voltage drop at 5mA.
  • LEDs and bicolour LEDs (2 lead and 3 lead types). Measures forward voltage drop of each LED element at 5mA.
  • Zener Diodes with measurement of zener voltage up to 9V at 5mA.
  • Voltage regulators (measures regulation voltage <8V, drop-out voltage, quiescent current). Note that some regulators are not stable without their decoupling caps and/or minimum load and cannot be tested by the DCA75.
  • Triacs and Thyristors that require less than 10mA of gate current and holding current.
Stand-alone or with a PC
The instrument can be used stand-alone or connected to a PC. Either way, the DCA Pro will automatically identify the component type, identify the pinout and also measure a range of component parameters such as transistor gain, leakage, MOSFET and IGBT threshold voltages, pn characteristics and much more.
Curve Tracing 
When connected to a PC using the supplied USB cable, a range of low current curve-tracing functions can be performed. Various graph types are available, with more to follow:
  • Bipolar transistor output characteristics, IC vs VCE.
  • Bipolar transistor gain characteristics, hFE vs VCE.
  • Bipolar transistor gain characteristics, hFE vs IC.
  • MOSFET and IGBT output function, ID vs VDS.
  • MOSFET and IGBT transfer function, ID vs VGS.
  • JFET output function, ID vs VDS.
  • JFET transfer function, ID vs VGS.
  • Voltage regulator, VOUT vs VIN.
  • Voltage regulator, IQ vs VIN.
  • PN junction I/V curves, forward and reverse options (for Zener diodes).
Curve tracing is performed using test parameters in the range of +/-12V, +/-12mA. All curve-tracing data can be instantly pasted into Excel© for further graphing and analysis. PC Software is included with the DCA Pro on a Peak USB memory stick. Software designed for Windows XP, Vista, Windows 7 and Windows 8 (automatically runs in Desktop Mode).
What's included?
  • DCA Pro instrument.
  • AAA Alkaline Battery.
  • Micro USB cable (approx 1m).
  • PC Software on USB Flash Drive (512MB).
  • Premium gold plated hook probes.
  • Comprehensive printed user guide.

A Selection of PC Screen-Shots
TIP121 Darlington with internal resistors and diode G4BC20U N-Ch IGBT
Common Anode Bicolour LED BTS141 N-Ch MOSFET (Smart type with gate protection)
Comparing LED colours - all with appropriately coloured plots 2N5401 PNP Transistor Output Characteristics
Comparing voltage regulators Comparing Zener diodes using reverse PN analysis
J111 N-Ch JFET Transfer Characteristic OC71 PNP Germanium gain variation
DCA Pro - A view inside - Display side DCA Pro - A view inside - Surface mount side
Atlas DCA (DCA55) and DCA Pro (DCA75) Comparison
  Feature Atlas DCA Atlas DCA Pro  
Display type 16 x 2 Alphanumeric 122 x 32 Graphic
Communications - USB (Win USB built-in driver)
Power supply 1 x GP23 12V battery 1 x AAA and USB power
Curve Tracing (on PC) - Yes
Test Signals Range (typ) +/-5V, +/-5mA +/-12V, +/-12mA
Test Signal Resolution 10 bits 12 bits
Voltage measurement resolution 20mV 3mV
Diode / LED support Yes Yes
Transistor support Yes Yes
MOSFET support Yes Yes
IGBT support - Yes
JFET support Yes Yes
Zener diode analysis - Yes
Voltage regulator analysis - Yes
JFET pinch-off measurement - Yes
JFET on-threshold measurement - Yes
JFET transconductance - Yes
Depletion mode threshold measurement   Yes
Saturation voltage measurement - Yes
Leakage current measurement Yes Yes
Online upgradeable firmware - Yes
Online upgradeable PC software N/A Yes
Sounder - Yes (with mute on/off)
Atlas DCA75 - Frequently Asked Questions (FAQs)
  Can the DCA75 be used in-circuit? No. It is not possible to take into account the influence of other unknown components around the component you're trying to test and results can be misleading. Also, it is possible that you may damage your instrument if there is any unexpected charge in your circuit. We know that it's not always easy, but we recommend that you test components that are not connected to other parts.  
Is the DCA75 ok with germanium transistors, can it measure leakage current and does it take into account the leakage current for it's gain measurement? Yes. The DCA75 will detect the germanium (or silicon) type of semiconductor. It will measure leakage current and it takes that leakage into account when measuring gain (unlike most multimeter hFE measurements).
I've noticed the leakage current of my germanium transistor gradually drop with each subsequent measurement. Is the battery failing or something else wrong? Leakage current is extremely temperature dependent and particularly noticeable for germaniums as the current is fairly high to start with. The leakage current can double for just a 5°C increase in temperature. So after some handling, the transistor temperature slowly falls and can lead to a decreasing leakage current. That's completely normal and correct. Additionally, DCA75 test currents are completely independent of battery condition.
The Collector and Emitter of my germanium transistor is showing the wrong way round, is the DCA75 wrong? If the leakage current of the germanium transistor is quite high (due to warming from your fingers for example), the DCA75 can reject the "correct" pinout. However, it will then search for all other device types and configurations. It can, in those circumstances, find a transistor with the C-E swapped (although gain can be very low). Tests in a simple circuit confirm that you can get a germanium transistor to work, with some gain, in that way. So the DCA75 is not wrong, it's just found a configuration that yields a low leakage current. Try keeping your transistor cool during testing to avoid this situation.
Can the Atlas DCA75 measure Zener diodes? Yes. The DCA75 can test Zener diodes up to around 11V. Zeners with a reverse voltage of less than around 8V will be tested at 5mA, higher voltage ones may be tested at a lower test current. The test current is confirmed on the display.
Can I use the DCA75 to match transistors? Yes. The main parameters that you may be interested in are hFE and VBE. Both of these parameters are measured by the DCA75. This enables you to group your transistors that have similar gain figures for example. Additionally, the use of the curve tracing facility allows even greater flexibility for your desired matching requirements.
Are Unijunction transistors (UJTs) supported? No. The DCA75 doesn't currently support UJTs although this is planned for a future release (to be available via online upgrade too).
My MOSFET has a separate "substrate" or "bulk" connection, what do I do with that lead? Some rare MOSFETs have 4 leads (gate, source, drain and substrate). To enable the DCA75 to test these, connect the substrate lead to the source lead. If your MOSFET does not have a body diode then you will also need to connect a diode across the drain-source leads.
What will the DCA75 show if my component is faulty? Generally, the DCA75 would show "No component found". Sometimes it may still be able to see a pn (diode) junction within the component you're testing, in which case it would display "Diode or diode junction(s)". If there is a short circuit within your component then the DCA75 will display "Short circuit on RED GREEN" for example.
Can my Atlas DCA75 be upgraded online? Yes. The PC software (available here) will check your instrument to make sure it's got the latest firmware, it will then offer to upgrade it for you.
Why can't the DCA75 analyse triacs or thyristors that need higher currents than 10mA? The test currents of the DCA75 are deliberately low to avoid damage to any potentially random component that can be connected any way round. The Peak Atlas SCR is aimed specifically at analysing a wide range of triacs and thyristors that require test currents from less than 100uA up to 100mA.
My voltage regulator won't test out correctly on the DCA75, what's wrong? There are many varieties of voltage regulator available and some can't be tested on the DCA75. Firstly, the regulator voltage needs to be around 8V or lower for it to be testable. Secondly, there are some regulators that just aren't stable unless they're in their intended circuit with decoupling caps and a suitable load.
Will you have software that can run on a Mac or under Linux available? We don't have immediate plans for releasing non-Windows software, although we are investigating the possibility.
I have a suggestion for a new supported component type or new feature, what can you do? We'd love to hear any new component or new feature suggestions. We're a flexible company and we'll do our best to implement new features when possible.
Is the battery used if I'm connected by USB? No. The instrument draws all the power it needs from the USB connection (if present).
How long is the warranty period? All our products now have a warranty of 24 months. This doesn't cover accidental damage or abuse however.

Summary specifications (at 25°C unless otherwise specified):

Parameter Min Typ Max Note
Bipolar Transistors        
Measurable current gain (hFE) range 2   32000 2
hFE accuracy (hFE<2000) ±3% ±5 hFE 2,8
hFE test voltage (VCEO) 3.0V   9.0V 2
hFE collector test current 4.75mA 5.00mA 5.25mA  
Base current for VBE measurement 4.75mA 5.00mA 5.25mA  
VBE accuracy ±1% ±0.006V 8
VBE resolution   3.0mV 6.0mV  
VBE for Darlington identification 0.95V 1.00V 1.80V 3
VBE for Darlington (shunted types) 0.75V 0.80V 1.80V 4
VBE threshold for germanium   0.55V    
Acceptable VBE     1.80V  
Base-emitter shunt threshold 50kΩ 60kΩ 70kΩ  
Acceptable collector leakage     1.5mA 6
Leakage current accuracy ±2% ±0.02mA  
Enhancement mode VGS(ON) range 0.0V   10.0V 5
Depletion mode VGS(ON) range -5.0V   0.0V 5
VGS(ON) accuracy ±2% ±0.01V 5
Drain current at VGS(ON) 4.75mA 5.00mA 5.25mA  
Drain-Source voltage at VGS(ON) 3.5V   9.0V 5
Acceptable gate-source resistance 8kΩ      
IGBT collector saturation threshold   0.40V   9
Pinch-off VGS(OFF) range -10.0V   2.5V  
Pinch-off drain-source current 4.5μA 5.0μA 5.5μA  
Turn-on VGS(ON) range -9.0V   2.5V  
Turn-on drain-source test current 4.75mA 5.00mA 5.25mA  
VGS accuracy ±2% ±0.01V  
Transconductance (gfs) range     99mA/V  
gfs test drain current span 3.0mA to 5.0mA  
gfs accuracy (<20mA/V) ±5% ±2mA/V  
gfs accuracy (<20mA/V) ±10% ±5mA/V  
Parameter Min Typ Max Note
Thyristors and Triacs        
Gate trigger test current 8.0mA 10.0mA 12.0mA 7
Load hold test current   10.0mA 15.0mA  
Diodes and LEDs        
Diode forward test current 4.75mA 5.00mA 5.25mA  
Diode forward voltage accuracy ±1% ±0.006V  
Acceptable VF for a diode @ 5mA 0.15V      
VF for LED identification 1.5V   4.0V  
Zener Diodes        
Zener voltage range at 5mA 1.8V   9.0V  
Zener voltage range below 5mA   9.0V 12.0V  
Zener diode test current 0.50mA 5.00mA 5.25mA  
Voltage Regulators        
Input test voltage range (IQ<3.0mA) 1.1V   10.0V  
Input test voltage range (IQ<5.0mA)     8.0V  
Quiescent current range (IQ) 0.00mA   5.00mA  
Quiescent current accuracy ±2% ±0.02mA  
Dropout voltage range (VDO) 0.0V   3.0V  
Dropout voltage accuracy ±2% ±0.02V  
Output voltage accuracy ±1% ±0.006V  
Load test current 0.13mA   1.25mA  
General Parameters        
Peak test current into S/C -15.5mA   15.5mA 1
Peak test voltage across O/C -13.5V   13.5V 1
Short circuit threshold 10Ω 20Ω 1
Battery type (x1) Alkaline AAA, LR03, MN2400
Battery voltage range 1.0V 1.5V 1.6V  
Battery warning threshold   1.0V    
USB current consumption 500mA pk active. ≤2mA sleep
Dimensions (body) 103 x 70 x 20 mm  
  4.1" x 2.8" x 0.8"  
Operating temperature range 10°C   40°C 10
  50°F   104°F 10


1. Between any pair of test clips.
2. Collector current of 5.0mA. Gain accuracy valid for gains less than 2000.
3. Resistance across reverse biased base-emitter > 60kΩ.
4. Resistance across reverse biased base-emitter < 60kΩ.
5. Load current of 5.0mA.
6. Collector-emitter voltage of 10.0V.
7. Thyristor quadrant I, Triac quadrants I and III.
8. BJT with no shunt resistors.
9. Load current typically 10.0mA.
10. Subject to acceptable LCD visibility.