I want to make 5kw class D amplifier , but getting confused in output stage ,,, IGBT vs Mosfet
I want high quality audio , comparable to linear amps ,,, I am new to class D
I want high quality audio , comparable to linear amps ,,, I am new to class D
Anything <10kVA is clearly within MOSFET jurisdiction. Besides, IGBTs do not conduct current in the reverse direction (the anti-parallel diode does the job) and that makes commutation very lossy. The MOSFET channel however is truly bidirectional and keeps the losses minimal in both the directions.
As mentioned, IGBT is for really high power.
IGBT is more for high voltage and high current applications needed in industrial environment where you need 400V, 1000V or more where mosfets don't have a good performance when using high currents (400A, 1000A or more).
In addition, IGBT are in general not so fast (<100kHz), but it is adequate for industrial applications.
For audio class D, you need fast switching frequencies (>400kHz), so mosfets are better.
For a 5kW amplifier, if using 4ohm load, you need V=sqrt(5000*4)=141Vrms or 199Vpeak and just moderate current level of 199/4=49.7A.
IGBT is more for high voltage and high current applications needed in industrial environment where you need 400V, 1000V or more where mosfets don't have a good performance when using high currents (400A, 1000A or more).
In addition, IGBT are in general not so fast (<100kHz), but it is adequate for industrial applications.
For audio class D, you need fast switching frequencies (>400kHz), so mosfets are better.
For a 5kW amplifier, if using 4ohm load, you need V=sqrt(5000*4)=141Vrms or 199Vpeak and just moderate current level of 199/4=49.7A.
do you need toroidal transformers for the PSU?
I have to sell really good potted 7kw toroids 230v/230v for cheap
unfortunately single secondary 230v
I have to sell really good potted 7kw toroids 230v/230v for cheap
unfortunately single secondary 230v
IGBT's or more suited to large brute force power supplies than audio amplifiers, although they can be pressed into that kind of service.
5 kW?
How big is the listening area?
That is stadium or hall level stuff.
A rock concert will be less than 30 kW for a 50,000 person audience.
And asking for good sound quality in an open air setting is a dream.
Contact a local seller, the plate amps and speakers etc. are readily available, you can go for several 1 kW units connected via Bluetooth.
And Mosfet, only one maker in India makes IGBT amps to my knowledge, and those people are in a steel town in Eastern India.
And give details of listening area, size in height, width, roof height, wall treatment, furniture etc.
I think you are getting confused between W RMS and W PMPO, the PMPO figures are sometimes imaginary.
How big is the listening area?
That is stadium or hall level stuff.
A rock concert will be less than 30 kW for a 50,000 person audience.
And asking for good sound quality in an open air setting is a dream.
Contact a local seller, the plate amps and speakers etc. are readily available, you can go for several 1 kW units connected via Bluetooth.
And Mosfet, only one maker in India makes IGBT amps to my knowledge, and those people are in a steel town in Eastern India.
And give details of listening area, size in height, width, roof height, wall treatment, furniture etc.
I think you are getting confused between W RMS and W PMPO, the PMPO figures are sometimes imaginary.
IGBTs are slow, but much more robust at high voltage (100's of volts), so they dominate mains inverters, car chargers, industrial motor control etc. They typically come in only two voltage ratings, 600 and 1200V. They have huge losses in low voltage circuits, and are not resistive so produce non-linearity as well.
They are usually rated for lower currents than equivalent MOSFETs purely because of the loss-voltage setting thermal limits. Big MOSFETs can be < 0.0005 ohms, IGBTs have ~2V of loss, if the package is 500W rated the MOSFET could carry 1000A, the IGBT only 250A (package permitting!)....
But as I said using MOSFETs at say 400V is very tricky to get right, they are sensitive to high dV/dt on the drain coupling to the gate via internal capacitance and blowing the whole device. IGBT's gate is protected from the collector dV/dt by extra layers inside the device...
They are usually rated for lower currents than equivalent MOSFETs purely because of the loss-voltage setting thermal limits. Big MOSFETs can be < 0.0005 ohms, IGBTs have ~2V of loss, if the package is 500W rated the MOSFET could carry 1000A, the IGBT only 250A (package permitting!)....
But as I said using MOSFETs at say 400V is very tricky to get right, they are sensitive to high dV/dt on the drain coupling to the gate via internal capacitance and blowing the whole device. IGBT's gate is protected from the collector dV/dt by extra layers inside the device...
There exist very high current purpose specified IGBTs. Most very high power high efficiency UPS have them both in rectifier and in inverter. Usually 1200V types and they exist in 2400A versions.
Oh and they can explode spectacularly when things go wrong 🙂
Oh and they can explode spectacularly when things go wrong 🙂
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A 100A IGBT usually has a Vcesat of 2V, giving a loss of 200W at rated current. But, a 100A MOSFET that has a 10mohm Rdson at rated current gives just 100W. Now, at reduced current say 10A the IGBT loss is almost 20W but the MOSFET dissipates only 20^2*10m = 4W and thus is the clear winner.
Most IGBTs also need a bipolar gate drive (+15/-10) for complete turn off, which could be another disadvantage vs. MOSFETs.
Most IGBTs also need a bipolar gate drive (+15/-10) for complete turn off, which could be another disadvantage vs. MOSFETs.
Not as IGBTs are usually the weapon of choice in high reliability industrial devices for high power 24/7 operation. Vcesat has been reduced and other techniques are implemented.
https://www.renesas.com/en/document..._r-HS0t8EmpCKYUQGQ9DeSICJ12MJGwqSXnoSuMyW1j3B
https://www.mitsubishielectric.com/...ces/products/power-module/igbt-module-3level/
Yes that bipolar gate drive or negative bias is a drawback but a fact of life. This is very critical as any failure in such a circuit is instant catastrophe. Much attention is giving to understand the negative bias circuits and the relevance of verification of correct operation. Often various programs for slow start and/or reduced output voltage can be chosen after maintenance or repair to reduce the failure possibilities while charging the DC bus etc. Sometimes even drive boards are replaced during maintenance as preventive measure.
MOSFETs usually are used till 4 kVA output power. This is all not opinion but reality.
https://www.renesas.com/en/document..._r-HS0t8EmpCKYUQGQ9DeSICJ12MJGwqSXnoSuMyW1j3B
https://www.mitsubishielectric.com/...ces/products/power-module/igbt-module-3level/
Yes that bipolar gate drive or negative bias is a drawback but a fact of life. This is very critical as any failure in such a circuit is instant catastrophe. Much attention is giving to understand the negative bias circuits and the relevance of verification of correct operation. Often various programs for slow start and/or reduced output voltage can be chosen after maintenance or repair to reduce the failure possibilities while charging the DC bus etc. Sometimes even drive boards are replaced during maintenance as preventive measure.
MOSFETs usually are used till 4 kVA output power. This is all not opinion but reality.
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International Rectifier had managed to make IGBTs that did not need the negative gate drive and worked perfectly using MOSFET gate driver ICs.
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d462533600a401535743b1863f04
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d46250cc1fdf0151006efeed2394
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d462533600a401535743b1863f04
The best Vce sat I've seen in production IGBTs is 1V, never lower but that is still high considering what MOSFETs can do.
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d46250cc1fdf0151006efeed2394
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