Is uc3844 used nowadays

[phobos1]

Is uc3844 used in smps design these days ? If yes why ?

There are a lot of switching ICs in the market with inbuilt Mosfets.

 

[treez]

uc3844 used very much, ..internal fets on those other monolithic chips are often poor.
uc3844 is great current mode controller, some say it is more robust than ucc38c44 which was supposed to replace it.

 

[Mr.Cool]

check with manufacturers planned obsolescence schedule. that chip will be used in high volume right up to the day it goes obsolete. it was too popular so now its used a lot and nobody will re-design their product to use some other until that thing goes obsolete.

 

[treez]

I don't think it ever go obsolete......they use it in harsh environments because it is bipolar and is more robust than cmos ones.

give me a uc3844 any day.....implement your protection features externally, its so much more intuitive...just a bare current mode controller...perfect.

 

[treez]

here is a thread which compares the uc384x with the later ucc38c4x parts

https://www.edaboard.com/threads/335190/

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so why is the uc384x family still used, when the seemingly better ucc38c4x family now exists?

Well the answer must surely be that the uc38c4x family is more robust against ESD events. Surely that can be the only realistic answer?

(also the uc38c4x family has a higher allowable input "vcc" voltage)

Strangley, one is often recommended to add a schottky from gate drive output to gnd (anode to gnd) for the uc384x devices, but one is never recommended to do this with the ucc38c4x devices.

There are a lot of switching ICs in the market with inbuilt Mosfets.

..yes..likE the power integrations topswitch family, but they are voltage mode, and they give you the feedback loop circuit, but if that opto goes obsolete, then you have to re-do a voltage mode feedback loop with the replacement opto...not as nice a place to be in when compared to just having a plain old current mode controller.

tHEY MADE TOPSWITCH IN VOLTAGE MODE BECAUSE THEY COULDNT MAKE THEIR DESIGN SOFTWARE MAnage slope compensation, but in reality , this is a poor situation (sorry about caps)...give me a uc3842 current mode controller any day...ill put the slope compensation in myself.

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The below thread talks about the diode connected from gate drive output to ground on the uc384x (it actually concerns the lt1241 but that is an equivalent part to uc384x)
https://www.edaboard.com/threads/158967/

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The LT124X series of chips clain to be an improved replacement for the UC384X family, but doesn't clearly say why it really is better than the uc384x devices (if it is actually better at all)
Also, the LT1241 does not say whether or not it is an improvement over the UCC38C4X family

LT1241 datasheet
http://cds.linear.com/docs/en/datasheet/1241fa.pdf

Thread about LT1241 and the diode connected form gate drive output to gnd (is this diode needed for ucc38c4x...who knows?)
https://www.edaboard.com/threads/158967/

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Working on a contract for a customer who wants an smps designed in three seconds?.....use a simple uc384x (or ucc38c4x) device!........because all the others require long datasheet reads, and the customer won't let you read a datasheet because you should have memorised every datasheet on the planet anyway!...look at the size of the topswitch datasheets!