Replace IRF540 in IRFZ44

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Are you sure those IRF540s are part of the power supply?

IRFZ44 has lower input capacitance [no need to change gate drive], similar output capacitance [no need to change RC damping networks] and much lower Rds-on so it will be a great replacement for IRF540 in any 12V push-pull SMPS

Anyway, all car-audio amplifiers I've seen using IRF540 for SMPS were essentially worthless. Apparently those amplifier designs had undergone so extreme cost reduction processes that manufacturers didn't hesitate to save some more cents of dollar by using IRF540 instead of IRFZ34 or IRFZ44 on the SMPS

[JBL has been applying severe cost and quality reduction policies to its car audio market for some years]
 
Oh, IRFxx prices vary a lot over time and depending on the quantity and procedence of the devices, but as an exmaple, when some chinese car amplifier manufacturer has 10.000 IRF540 in stock and there is no demand for MOSFET output stages it's allways cheaper to use them for SMPS than to buy another 10.000 IRFZ34 or IRFZ44 and eat the 10.000 IRF540 with potato chips :D
 
Replacament for IRFZ44?!

Oh, IRFxx prices vary a lot over time and depending on the quantity and procedence of the devices, but as an exmaple, when some chinese car amplifier manufacturer has 10.000 IRF540 in stock and there is no demand for MOSFET output stages it's allways cheaper to use them for SMPS than to buy another 10.000 IRFZ34 or IRFZ44 and eat the 10.000 IRF540 with potato chips :D
What is the replacement for IRFZ44?:confused:
thanks
 
Interesting post Eva as always. It is interesting that you say that all car amps which have the IRF540 are worthless. Can you please explain why? Does the high Rds ON resistance affect the sound quality or is it just an efficiency issue. I recently built a car amplifier using a pushpull converter plus 2 x LM3875 for stereo operation. I used 4 x IRF540 (2 on each side) as the switching mosfets and the sound was not the same as running it from the toroidal. It was as if there was something missing. It lacked vitality. Lets see what you have to say about this.
 
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