IGBT Replacement. - Page 1
Forum section: electronics / repair

author: Oneminde
author_rank: Regular Contributor
timestamp: September 06, 2016, 12:34:06 am
content: In a Russian forum, a member needed to replace a IGBT called GT2810/MSGT2810, another member stepped in an mentioned IRFP 24N50. So he replaced it with the 24N50 and it worked.N-Channel MOSFET 24A 500Vhttp://www.mouser.com/ds/2/205/9ad740a9-e21c-47ce-b454-fc3a9ba842d9-65407.pdfAlso found this:Fairchild FGH50N6S2D600V, SMPS II Series N-Channel IGBT with Anti-Parallel Diode.75/60A 600V and the symbol is correct in relationship to the schematic.https://www.fairchildsemi.com/datasheets/FG/FGH50N6S2D.pdfAre these two devices the same?

author: Oneminde
author_rank: Regular Contributor
timestamp: September 06, 2016, 12:50:45 am
content: FGA3060ADF600 V, 30 A Field Stop Trench IGBThttps://www.fairchildsemi.com/datasheets/FG/FGA3060ADF.pdf

author: Oneminde
author_rank: Regular Contributor
timestamp: September 06, 2016, 10:31:36 am
content: Hello AcHmed99.This is the output stage of Focal FPS line of amplifiers. Most of them use the GT2810. 6 per channel for the 2300RX which I use in this example (pic)Maximum output at 14.4V @ 2ohm load (bridged) is 1 x 750W.Maximum output at 14.4V @ 1ohm load (stereo) is 2 x 430 WFocal state that it is a Insulated-gate bipolar transistor, so no question about the fact that it is a IGBT.I have attached the power sch and amplifier sch - the other is crossover etc

author: Oneminde
author_rank: Regular Contributor
timestamp: September 06, 2016, 03:48:10 pm
content: I've learned a few things since last night.One is that Turn-On Delay Time, Rise time, Turn-off delay time and Fall time, the faster it is, the better the musical quality - as in it switches faster between tonal changes.Did some calculations for 4 ohm load.Stereo mode: 4 x 120W = 60 W pos/neg.Bridged mode: 2 x 380 W = 190 W pos/neg.The circuit breaker per side (2 Chn) is 40A, this must then also be divided by pos/neg, so 20A and side. (stereo)In bridged mode, you could potentially get upwards of 380W / 14.4V = 26,38A but with losses in the system, this is only a theoretical number.So, what I have so far is that the IGBT I need should be able to reach the potential 190W (peek), low Threshold Voltage for turn on (<5V) and low turn on, rise, fall and turn off.

author: Oneminde
author_rank: Regular Contributor
timestamp: September 06, 2016, 07:38:46 pm
content: Thanks for checking in again AcHmed99.I will try to aid you as much as possible.First of, the amp is Focal FPS 4160. My goal is to replicate it - for myself - in an old school style, meaning through hole components when available. I don't aim to change anything, only tighter tolerances for quality. Since this is a class A/B, rise, fall, on and off time isn't as sensitive as if it were a class D as far as I understand.Found this info in another thread: The main advantage of IGBT over MOSFET in high voltage switching applications is much lower conduction losses given the same package or die size. Switching losses are higher, though. CheckSGH80N60UFfor example, Vce-sat for 40A is only 2.1V in the 25ºC to 125ºC temperature range. Any similar MOSFET would exhibit a two or three-fold increase in Rds-on at 125ºC with respect to 25ºC.ToshibaEquivalent circuit of an IGBT is shown below. An NPN transistor is designed not to be driven by RBE. Applying ON signal to gate of an Nch MOSFET changes conduction state. As a result, base current flows from emitter to base. This base current decreases ON resistance of the Nch MOSFET. (conductivity modulation effect).Also, when working bellow 20kHz, the efficiency of a IGBT is equal to that of a MOSFET.As you mentioned, switching time isn't relevant.The output of this amp is:@ 14.4V - 4 ohm load Stereo: 4 x 120W@ 14.4V - 4 ohm load Bridged: 2 x 380W@ 14.4V - 4 ohm load Stereo & Bridged: 2 x 120W + 1 x 320WI arrive at the amp figure by 380W / 14.4V = 26,38A meaning the IGBT should be able to handle this. So a 30A collector current at 100 C degree would be desireble - headroom is always nice. Most IGBT's today have 500, 600 or 650V ratings, so that should not be a problem either. IGBT's have come a long way since the 80's and 3'rd and 4th generations are common.Found a few IGBT's of interest:Fairchild SGH80N60UF:https://www.fairchildsemi.com/datasheets/SG/SGH80N60UFD.pdfas well as Fairchild FGA40T65SHDF, FGA3060ADF (interesting)Infineon SKW30N60:http://www.infineon.com/dgdl/Infineon-SKW30N60-DS-v02_03-en.pdf?fileId=db3a304412b407950112b427ee0f3d1eROHM RGTH60TS65D:http://rohmfs.rohm.com/en/products/databook/datasheet/discrete/igbt/rgth60ts65d.pdfand theToshiba GT50J325:http://www.farnell.com/datasheets/58133.pdfAlso Toshiba list and Fairchild list of IGBT'shttp://toshiba.semicon-storage.com/list/index.php?f%5B%5D=6%7CYes&f%5B%5D=9%7CTO-3P%28N%29&f%5B%5D=4%7C600&p=&h=&sort=0%2Casc&code=param_308&region=apc&lang=en&cc=0d%2C1d%2C3d%2C4d%2C5d%2C6d%2C7d%2C8d%2C9d%2C10d&scroll_x=0&scroll_y=0https://www.fairchildsemi.com/products/discretes/igbts/discrete-igbts/#N=4294886700+4294817524&&Ns=P_IGBT_DISCRETE_FALL_TIME|0&&showAll=true&&showHrd=false&&rq=IGBT_BVCES_MIN%3C%3E600,650If you want more info on the amps, schematic etc, I can fix that.

author: Oneminde
author_rank: Regular Contributor
timestamp: September 06, 2016, 08:30:28 pm
content: Just want to add this Infineon IKW30N60H3 IGBT. Fairly low saturation voltage.http://www.mouser.com/ds/2/196/IKW30N60H3_2_2-80301.pdf

author: Oneminde
author_rank: Regular Contributor
timestamp: September 06, 2016, 09:02:02 pm
content: Even better. All new IGBT from Infineon.IKW30N60DTP - 600V - 30A - 1.6V (sat) - 175°C - PG-TO247-3Overall low losses and nice performance.http://www.digikey.ca/product-detail/en/infineon-technologies/IKW30N60DTPXKSA1/IKW30N60DTPXKSA1-ND/6131398http://www.mouser.se/ProductDetail/Infineon/IKW30N60DTPXKSA1/?qs=%2fha2pyFaduhdbnymSgoOaFFOZ4LgwfGZjGRS597LWAxaRjjfPNgqHrzZKyLcaKpWDatascheet:http://www.infineon.com/dgdl/Infineon-IKW30N60DTP-DS-v02_01-EN.pdf?fileId=5546d46253a864fe0153cbb98d0e7cac

author: MagicSmoker
author_rank: Super Contributor
timestamp: September 06, 2016, 11:13:53 pm
content: Although you can make an amplifier with damn near any kind of transistor, some are better suited to the job than others; I'd place modern IGBTs at the bottom of the heap.MOSFETs optimized for linear use would be much a more preferable "drop-in" replacement for the IGBTs in that schematic. IXYS L2 series are good.A low saturation voltage is meaningless in a linear amplifier unless you like it to spend most of its time in clipping. Similarly, low switching losses/fast switching speeds are equally useless as you aren't trying to slew hundreds of volts in tens of nanoseconds (more like tens of volts in tens of microseconds, max).

author: Oneminde
author_rank: Regular Contributor
timestamp: September 06, 2016, 11:54:50 pm
content: Quote from: MagicSmoker on September 06, 2016, 11:13:53 pmThanks for your input and I will read up on IXYS L2 tomorrow. It is true that the amp operate in a linear mode, but humour me for a moment.2 questions for you MagicSmokerFocal, known to generally produce great stuff, why did they select IGBT over MOSFET ? The FPS series have gained awards and people are generally happy with the performance. It would be interesting to get your speculation on it.While it is also true that rise, fall, on and off time isn't as crucial for class A/B as it is for class D operating in switch mode. Musical quality is related to a transistor/MOSFET ability to change in relationship to hertz. Higher tones require less power than a low tone. How is the selection of IGBT compared to MOSFET related ?http://www.electronicproducts.com/Analog_Mixed_Signal_ICs/Discrete_Power_Transistors/MOSFET_vs_IGBT.aspxQuote

author: MagicSmoker
author_rank: Super Contributor
timestamp: September 07, 2016, 12:13:25 pm
content: Quote from: Oneminde on September 06, 2016, 11:54:50 pmNovelty factor?*Like I said, you can make an amplifier out of pretty much any transistor (ie - BJT, JFET, MOSFET, IGBT) - mainly because the magic of negative feedback will ensure it reproduces signals with "high fidelity" regardless of the transistor used - but that doesn't mean that ALL transistors are equivalently suited to the job. Broadly speaking, transistors can be optimized for switching or linear operation, and trying to use one optimized for switching in a linear application usually results in disaster unless heavy derating is employed (that is to say, the devices are operated far below the voltage and current ratings stated in the datasheet). Conversely, using a device optimized for linear operation in a switching application usually only results in higher losses (mainly conduction), but rarely in outright failure.In the case of MOSFETs, arranging the drain and source horizontally ("lateral"), similar to how a JFET is constructed, optimizes linear operation, while the vertical arrangement ("VMOS", "DMOS", and similar) with source on top and drain on bottom results in better switching performance (as defined by lower Rds at higher breakdown voltages, mainly). Similar distinctions in construction and optimization apply to BJTs (less so to IGBTs and JFETs, which tend to be more optimized only for switching and linear operation, respectively), but with respect to IGBTs there is a critical difference in how they behave during turn off that makes them especially unsuited to linear operation: the "control" MOSFET has no influence on how fast the "power" PNP bipolar turns off; that is strictly a function of minority carrier recombination time. Which is to say, you can control how fast an IGBT turns on via the gate, but not how fast it turns off. This results in what is called "tail current" flowing from the IGBT for some period of time, though as explained later this stuff happens on fairly short time scales compared to music waveforms. Furthermore, the power PNP portion of the IGBT can suffer from the insidious "second breakdown" phenomenon when operated in linear mode; I would expect you'd have to derate both voltage and current to 1/4th to perhaps as little as 1/10th the values allowed in switchmode operation, necessitating more devices in parallel for a given power output which then brings in fidelity problems from the inevitable mismatch in parameters.Unfortunately for hi-fi amplifier geeks, there are far more switching power supplies made every year than high power audio amplifiers, so the vast majority of MOSFETs - and virtually every single IGBT - are optimized for switchmode use. Only BJTs (and, at lower power, JFETs) seem to have a broad selection of devices optimized for linear operation, and even then there is less of a penalty from using a switchmode optimized BJT in a linear amplifier.For a pertinent example: note that all of the voltage amplification (ie - everything before the totem pole output stage) in that Focal amplifier is performed by BJTs...Quote from: Oneminde on September 06, 2016, 11:54:50 pmThat link is to an article comparing the relative merits of IGBTs and MOSFETs in *switching* applications, and as explained above, how a device behaves when it only has to switch between fully on and fully off does not necessarily translate into how it will behave when asked to smoothly slide between "mostly on" and "mostly off" (in Class A and Class AB there is always some bias current flowing, so the devices are never fully off).As for rise and fall (and delay) times, they aren't even crucial for Class D amplifiers except with regards to switching losses - which is to say, they have virtually no effect on fidelity. This is because all of these times are in the tens of nanoseconds range, which is several orders of magnitude shorter than anything in audio. For example, the period of a 20kHz sine wave is 25 microseconds, so to accurately reproduce it at 100W into an 8R load (ie - 28V) requires a slew rate of ~7V per microsecond (7V/us); that is, it can take ~4us to slew from 0V to 28V and still reproduce the waveform accurately. A MOSFET (or IGBT) that takes 50ns to slew from 0 to 100V or whatever is thousands of times faster than necessary, then.* - see, for example, the post by Nelson Pass on this diyaudio thread:http://www.diyaudio.com/forums/solid-state/908-has-somebody-used-igbt-power-amp.html

author: Oneminde
author_rank: Regular Contributor
timestamp: September 07, 2016, 04:57:34 pm
content: - I made a reply in the thread you linked to:http://www.diyaudio.com/forums/solid-state/908-has-somebody-used-igbt-power-amp-4.html#post4823457- and copied the text.For what its worth, I am going to drop a reply in this thread. Originally I was working in another thread I created a few days ago regarding IGBT replacement in an existing amplifier manufactured by a brand that is known for excellent products. Ofc as with everything ells, one can talk about brand attachment and such, but I would not say that is the case here. I just happened to like the spec.My goal is to “replicate” this amp for my own amusement and for the fun of doing so and turn it into an old school style with through hole components and narrow tolerances.I notice that this thread is very old, spanning over 15 years.Mister Nelson Pass made his reply back in 2001, that is 15 years ago. Surely that must matter, for if not, then IGBT’s and MOSFET has seen no evolution since they came out.Let’s look at an article from 1999The Insulated Gate Bipolar Transistor (IGBT).University of Glasgow - Schools - School of EngineeringStructureFig.1 shows the structure of a typical n-channel IGBT. All discussion here will be concerned with the n-channel type but p-channel IGBT's can be considered in just the same way.OperationBlocking OperationThe on/off state of the device is controlled, as in a MOSFET, by the gate voltage VG. If the voltage applied to the gate contact, with respect to the emitter, is less than the threshold voltage Vth then no MOSFET inversion layer is created and the device is turned off. When this is the case, any applied forward voltage will fall across the reversed biased junction J2. The only current to flow will be a small leakage current.The forward breakdown voltage is therefore determined by the breakdown voltage of this junction. This is an important factor, particularly for power devices where large voltages and currents are being dealt with. The breakdown voltage of the one-sided junction is dependent on the doping of the lower-doped side of the junction, i.e. the n- side. This is because the lower doping results in a wider depletion region and thus a lower maximum electric field in the depletion region. It is for this reason that the n- drift region is doped much lighter than the p-type body region. The device that is being modelled is designed to have a breakdown voltage of 600V.The n+ buffer layer is often present to prevent the depletion region of junction J2 from extending right to the p bipolar collector. The inclusion of this layer however drastically reduces the reverse blocking capability of the device as this is dependent on the breakdown voltage of junction J3, which is reverse biased under reverse voltage conditions. The benefit of this buffer layer is that it allows the thickness of the drift region to be reduced, thus reducing on-state losses.On-state OperationThe turning on of the device is achieved by increasing the gate voltage VG so that it is greater than the threshold voltage Vth. This results in an inversion layer forming under the gate which provides a channel linking the source to the drift region of the device. Electrons are then injected from the source into the drift region while at the same time junction J3, which is forward biased, injects holes into the n- doped drift region (Fig.2).This injection causes conductivity modulation of the drift region where both the electron and hole densities are several orders of magnitude higher than the original n- doping. It is this conductivity modulation which gives the IGBT its low on-state voltage because of the reduced resistance of the drift region. Some of the injected holes will recombine in the drift region, while others will cross the region via drift and diffusion and will reach the junction with the p-type region where they will be collected. The operation of the IGBT can therefore be considered like a wide-base pnp transistor whose base drive current is supplied by the MOSFET current through the channel. A simple equivalent circuit is therefore as shown in Fig.3(a)Fig.3(b) shows a more complete equivalent circuit which includes the parasitic npn transistor formed by the n+-type MOSFET source, the p-type body region and the n--type drift region. Also shown is the lateral resistance of the p-type region. If the current flowing through this resistance is high enough it will produce a voltage drop that will forward bias the junction with the n+ region turning on the parasitic transistor which forms part of a parasitic thyristor. Once this happens there is a high injection of electrons from the n+ region into the p region and all gate control is lost. This is known as latch up and usually leads to device destruction.- end of article -Lets move forward.http://www.infineon.com/dgdl/choosewisely.pdf?fileId=5546d462533600a40153574048b73edcIOR article:IGBT or MOSFET: Choose Wisely by Carl Blake and Chris Bull, International RectifierIGBT or MOSFET: Choose Wisely by Carl Blake and Chris Bull, International RectifierWith the proliferation of choices between MOSFETs and IGBTs, it is becoming increasingly difficult for today’s designer to select the bes t device for their application. Here are a few basic guidelines that will help this decision - making process.Device Evolution: Bipolar Transistors, MOSFETs and IGBTsThe bipolar transistor was the only “real” power transistor until the MOSFET came along in the 1970’s. The bipolar transistor requires a high base current to turn on, has relatively slow turn - off characteristics (known as current tail), and is liable for thermal runaway due to a negative temperature co - efficient. In addition, the lowest attainable on - state voltage or conduction loss is governed by the collector - emitter saturation voltage V CE(SAT).The MOSFET, however, is a device that is voltage - and not current - controlled. MOSFETs have a positive temperature co-efficient, stopping thermal runaway. The on-state-resistance has no theoretical limit, hence on-state losses can be far lower. The MOSFET also has a body drain diode, which is particularly useful in dealing with limited free wheeling currents.All these advantages and the comparative elimination of the current tail soon meant that the MOSFET became the device of choice for power switch designs.Then in the 1980s the IGBT came along. The IGBT is a cross between the bipolar and MOSFET transistors (see figure 1). The IGBT has the output switching and conduction characteristics of a bipolar transistor but is voltage - controlled like a MOSFET. In general, this means it has the advantages of high-current handling capability of a bipolar with the ease of control of a MOSFET. However, the IGBT still has the disadvantages of a comparatively large current tail and no body drain diode. Early versions of the IGBT are also prone to latch up, but nowadays, this is pretty well eliminated. Another potential problem with some IGBT types is the negative temperature co-efficient, which could lead to thermal runaway and makesthe paralleling of devices hard to effectively achieve. This problem is now being addressed in the latest generations of IGBTs that are based on “non-punch through” (NPT) technology. This technology has the same basic IGBT structure (see Figure 1) but is based on bulk-diffused silicon, rather than the epitaxial material that both IGBTs and MOSFETs have historically used.MOSFETs and IGBTs: Similar But Different.When comparing Figures one and two, the MOSFET and IGBT structures look very similar. The basic difference is the add ition of a p substrate beneath the n substrate. The IGBT technology is certainly the device of choice for breakdown voltages above 1000V, while the MOSFET is certainly the device of choice for device breakdown voltages below 250V.Between 250 to 1000V, there are many technical papers available from manufacturers of these devices, some preferring MOSFETs, some IGBTs. However, choosing between IGBTs and MOSFETs is very application-specific and cost, size, speed and thermal requirements should all be considered.IGBTs have been the preferred device under these conditions:• Low duty cycle• Low frequency (<20kHz)• Narrow or small line or load variations• High-voltage applications (>1000V)• Operation at high junction temperature is allowed (>100°C)• >5kW output powerMOSFETs are preferred in:• High frequency applications (>200kHz)• Wide line or load variations• Long duty cycles• Low-voltage applications (<250V)• < 500W output powerThe hard-switched measurements clearly show the lower losses of the MOSFET in their applications. Chart 1 shows that the losses of the IGBT are approximately equal to the losses of an IRFP460 if the switching speed is reduced to 50 kHz. This could allow a smaller IGBT to replace the larger MOSFET in some applications.This was the condition in 1997.However, the newer lower charge MOSFETs now available lower the losses at high frequency and therefore re-asserted the dominance of MOSFETs in applications using hard switching above 50kHz.Chart 2 shows the losses in an application using Zero Voltage Switching at 50kHz, 500W, the IGBT losses of 9.5W are higher than the MOSFET losses of 7W at room temperature. When the temperature is raised up to operating conditions however, the conduction losses of the MOSFET rise more quickly than the switching losses of the IGBT. The losses at elevated temperature increase 60% for the MOSFET while the total losses for the IGBT increase only 20%. At 300 watts this makes the power almost equal, while at 500 watts the advantage goes to the IGBT.Chart 3 shows the losses at 134kHz, 500W, elevated temperature, the IGBT losses of 25.2W are slightly worse than the MOSFET, with total losses of 23.9W. At room temperature in this same application the losses were 17.8 and 15.1 watts respectively. The switching losses are higher at higher frequency which eliminates the advantage of the IGBT at high temperature, when switching at the lower frequency. This illustrates the subject of this paper, namely there is no iron clad rule which can be used to determine which device will offer the best performance in a specific type of circuit. Depending upon the exact power level, devices being considered, the latest technology available for each type of transistor, the results will change slightly.Some of the conclusion:Finally, there seems to be an industry wide perception that MOSFETs are a mature product, which will not offer significant performance improvements in applications and IGBTs are a new technology, which will replace MOSFETs in all applications above 300 volts. No such generalizations are ever true and the huge improvements in MOSFET performance over the last two years certainly confirms that MOSFETs are a very dynamic product, and continues a trend of rapid growth. In fact, new low-charge MOSFETs such as the International Rectifier IRFP460A and IRFP22N50A significantly move performance benchmarks just when the IGBTs appear to offer an alternative in hard-switched applications.Infineon Showcases 650V TRENCHSTOP™ 5 – Performance of est-in-Class IGBT Gains High Customer DemandInfineon Showcases 650V TRENCHSTOP 5 &ndash; Performance of Best-in-Class IGBT Gains High Customer Demand - Infineon TechnologiesMore:http://www.infineon.com/dgdl/Infineon-ApplicationNote_DiscreteIGBT_DatasheetExplanation-AN-v01_00-EN.pdf?fileId=5546d462501ee6fd015023070b8b306dhttp://www.infineon.com/dgdl/an-983.pdf?fileId=5546d462533600a40153559f8d921224http://www.infineon.com/dgdl/an-990.pdf?fileId=5546d462533600a40153559fae19124eIGBT generation 3,4,5 and 6 have surfaced since late 90's.In the end what we are looking for is an amplifier that perform well as sound magnificent and the difficult part is what sounds magnificent? That will almost always be a subjective answer. Does a CD sound better than an vinyl record? perhaps, perhaps the CD (digital) is better when it comes to bass notes which vinyl cannot reproduce with the same dynamic range.Is a tube amplifier worse than a JFET, VFEt or MOSFET amplifier... actually, its different. Efficiensy is only one aspect of things. Some swear by class A amplifiers while some swear by class D.Some listen to music while some analyse the music. Some don't care about aesthetic aspects while some will pay $10 000 for something that looks good.My conclusion is that in order to select what I enjoy, I must test both IGBT and MOSFETS, even a Bipolar Transistor.

author: Oneminde
author_rank: Regular Contributor
timestamp: September 07, 2016, 10:26:04 pm
content: I understand your argument. I guess I had to read up some on IGBT's since I didn't know about their existence until a few day's ago.To really know what works one must try and have a blast doing so.What or which ones are the L2 Fets 100VD

author: Oneminde
author_rank: Regular Contributor
timestamp: September 07, 2016, 11:13:43 pm
content: You meant 100vdc, got you. I don't minde higher voltage breakdown. Its like a performance engine during day-to-day commute ... he he. And TO3P or TO-247 package is the plan yes.