the replacer of TOP232G

Posted by: jjl3 on 04/05/2012

in the former products the TOP232G was used.
Now I want to use TOP252G to repalce of TOP232G.
but I can not understand why R8 and V2 were added.
I only need Vuv is about 75VAC and .
can I change TOP232G to TOP252G, just increasing the values of resistors(R5,R6,R7) to about 940K?
can I use LNK305?

I need expert's suggestions.

thanks!
Br
jjl3

Comments

For your application it looks like LNK305 would be a better choice. Please refer to data sheet App note for LNK-TN

thanks for your reply!
how can I set Vuv?
how to understand R8 and V2?

Vuv function is simply overpower threshold which triggers auto-restart.

could you teach me how to set Vuv(75VAC or 80VDC) function on the device of LNK305?

thanks!
Br
jjl3

There is no Vuv_on specifically -- the device will simply turn on when it internally has sufficient bias which is typically 60VDC. If device cannot regulate it will go into auto-restart

I can find the 60VDC in datasheet of LNK305.
is it drain supply voltage?

thanks!
br
jjl3

Yes