Smps SG3525 syncronization

[fasafyso]

Hi experts. I searched forum for SYNC pin of SG3525 for what does it for. As i read the posts i saw that it is for syncronizing audio amplifiers. is it just for audio amplifiers. And why do we use syncronization, i mean what do we achieve if we use it and on which circumstances it must be used. what is its benefits??

Thanks.

 

[luka]

Hi

There will/should be no beating between supply and amp, amp should have even lower noise level. Most of the times you don't need to do this...

 

[fasafyso]

Hi

There will/should be no beating between supply and amp, amp should have even lower noise level. Most of the times you don't need to do this...

thank for reply. saying by regret but i couldnt understand what you mean while you are saying "beating" bec. i dont know its equivalent in my language. I have to ask what does beating stand for between supply and amp.

 

[megajocke]

If you have multiple switchers or a digital system one might want to synchronize them to make sure there are no difference freqencies that can be demodulated. With good filtering this should not be needed though.

 

[fasafyso]

thanks.

 

[Electrone]

thank for reply. saying by regret but i couldnt understand what you mean while you are saying "beating" bec. i dont know its equivalent in my language. I have to ask what does beating stand for between supply and amp.

Beating is a new lower frequency which results from the interference of two or more higher frequencies. Heterodyning (from root wood heterodyne) is another term for it.

 

[fasafyso]

Beating is a new lower frequency which results from the interference of two or more higher frequencies. Heterodyning (from root wood heterodyne) is another term for it.

Electrone thanks for reply. This new term "heterodyning" cleared out it more. Also for those who are interested in this subject Wikipedia has good explanation for both heterodyning which is a telecommunications electronics term and its variant "beating" which is a term for acoustic science.

http://en.wikipedia.org/wiki/Heterodyning
http://en.wikipedia.org/wiki/Beat_(acoustics)

 

[Electrone]

You're welcome, fasafyso.

 

[N-Channel]

Another application for the SG3525's SYNC pin is for one unit to run as a master, and all others to run as slave(s) to the master. Here, their internal clocks are disabled, but not the PWM sections. So, every module will clock out at exactly the same frequency as the master, eliminating the beat frequencies. The most familiar example of a beat frequency is when listening to an AM radio. A weak station sounds like it is "picket fencing", where the desired station fades in and out in a rapidly changing fashion.

 

[Karakacha]

hi, let me try to answer about the sync pin of sg3525 since I once worked using it
.....when using several chips,ie 2 or more, let one ber connected to give acertain frequency and make it a master.
......make it a clock to the others to make them slaves
......connect the sync pins together
.......hold down the oscillators of the slaves
Hence you would be able to clock several o/p