IGBT replacement

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Gaber Mohamed Boraey

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Hello everyone
Can I replace 11n120cnd with 40n120and?
Datasheets attached
 

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  • HGTG11N120CND.PDF
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  • FGL40N120AND.PDF
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The 40N120AND may dissipate more heat due to its higher current handling capacity. Check the thermal resistance and heat dissipation needs of your circuit to ensure it won't overheat in the new configuration.
 

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aliarifat794 said:
The 40N120AND may dissipate more heat due to its higher current handling capacity. Check the thermal resistance and heat dissipation needs of your circuit to ensure it won't overheat in the new configuration.
Click to expand...
Aha, there is a good heat sink, how you think about the speed?, which one is faster?
 

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I agree with @aliarifat794 . The electrical specs look better but for some unknown reason the junction thermodynamic specs look much worse.


So, if it failed from heat before, it may fail again. The speed depends on many things, such as Rce*C = Tau or Rce*Etot [W-s-ohm or [mJ-ohm], where the energy to charge is equal to the energy for each cycle of charge-voltage that must be charged by Rce.

Since the output switch capacitance must be charged with energy lost, comparing [mJ] * [Rce] total is a useful figure of merit (FOM).
This is the switch bulk resistance times capacitance-voltage.

For Rce(max), I use Vce(sat)/Ic @ Tmax= 3.5/11A = 0.315 Ohms = Rce in the 11N120

For original


So it is worth considering but temp. testing is needed.
 

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40n120 can be expected to show lower switching and conduction losses, but it needs about double gate current to achieve same switching speed. With 11n220 optimized gate driver, switching will be slower, thus you get possibly slightly increased losses if not modifying gate resistors.
As expectable, 40n120 has lower thermal resistance.
 

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How about 50n120and?
Attached datasheet
Or FGA25N120ANTD?
 

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  • NGTB50N120FL2W-D.PDF
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  • FGA25N120ANTD.PDF
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Last edited:

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If a better power switch is going to ripple more part changes out through the design, maybe you'd like one of the modules (been seeing a lot of them announcing lately; large scale renewables and traction seem to be lead markets). Power and right sized drivers, just "digital" input and big bang-bang.

Maybe desolder a little more and simplify your life, if it's your call to make.
 

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What are you talking about?
I repair, not design
Need equivelant number for the igbt
 
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I'm looking at gate_charge and switching energy (losses) in the first place. If they are similar or lower, the device should work as replacement. Presuming that current rating and respective static losses are o.k. as well.

Test in real hardware is nevertheless necessary.
 

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aha, understand, why you don't look at tr " rise time ", tf " fall time ", td on " delay on time ", td off " delay off time " , etc, these switching timing?
you worry more about heat?
 

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Timing and switching losses are related. If an inverter is designed with marginal deadtime, you might need to check timing separately, but I won't expect it for mainstream UPS inverters.
 

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