THis has been surgested before in other post but was never resolved.
On the Data sheet (page 4) it has the typical usage for the two IC's. Can I replace lm 4652 with 4 Mosfets to increase the output power and, hopefully, distortion? If I can what type of fets would I have to get (type wise eg. N channel etc.)?
Also on the sheet there is a pin for the oscillator, under the desciption of the resister that is off the pin it say it can adjust the frequency of the switching, are there any benefits from slower vs. faster?
one last minust thing... are RF chokes rated at 47mh (they go larger) suitable for the output inductors?
On the Data sheet (page 4) it has the typical usage for the two IC's. Can I replace lm 4652 with 4 Mosfets to increase the output power and, hopefully, distortion? If I can what type of fets would I have to get (type wise eg. N channel etc.)?
Also on the sheet there is a pin for the oscillator, under the desciption of the resister that is off the pin it say it can adjust the frequency of the switching, are there any benefits from slower vs. faster?
one last minust thing... are RF chokes rated at 47mh (they go larger) suitable for the output inductors?
Hi fr0st
First of all: Why do you want to increase distortion ? 😉 😕
Theoretically it would be possible to use four discrete N-channel mosfets.
Personally I wouldn't do it for the following three reasons:
1.) There's no mentioning of the drive capabilities of the modulator/driver IC (neither of the drive-needs of the output bridge) on the datasheet. You could end up with an unreliable amp.
2.) You will loose the termal protection functionality offered by this IC combination.
3.) You will have to deviate from the recommended layout. The layout is of paramount importance for any type of switching amplifiers. I do of course not want to keep you from experimenting with the layout but be aware that this might take some time.
Regarding the output filter: For what purpose do you want to use this amp (subwoofer ?) ?
Regards
Charles
First of all: Why do you want to increase distortion ? 😉 😕
Theoretically it would be possible to use four discrete N-channel mosfets.
Personally I wouldn't do it for the following three reasons:
1.) There's no mentioning of the drive capabilities of the modulator/driver IC (neither of the drive-needs of the output bridge) on the datasheet. You could end up with an unreliable amp.
2.) You will loose the termal protection functionality offered by this IC combination.
3.) You will have to deviate from the recommended layout. The layout is of paramount importance for any type of switching amplifiers. I do of course not want to keep you from experimenting with the layout but be aware that this might take some time.
Regarding the output filter: For what purpose do you want to use this amp (subwoofer ?) ?
Regards
Charles
What you see isn't necessarily what you get
Oftentimes, like most of the time, the PDF's will only reveal what the manufacturer wants to reveal, i.e. they only lift the kimona part way. I would stick with the LM4652 -- it's only about $5.50 in units anyway. National does give you the complete PCB layout, stuffing guide etc., and if there is any consideration that time=money, the LM4562 winds.
With regard to the output filters -- National adresses this specifically in their PDF -- although there is a typo.-- it's 50uH, not 50uF.
Oftentimes, like most of the time, the PDF's will only reveal what the manufacturer wants to reveal, i.e. they only lift the kimona part way. I would stick with the LM4652 -- it's only about $5.50 in units anyway. National does give you the complete PCB layout, stuffing guide etc., and if there is any consideration that time=money, the LM4562 winds.
With regard to the output filters -- National adresses this specifically in their PDF -- although there is a typo.-- it's 50uH, not 50uF.
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