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Power Supply design........

Started by mall...@yahoo.co.in August 5, 2009
HI!
I don't know i can ask this question or not here....

Actually we have a design based on BF532 which contains USB,Ethernet,VIDEO, audio and other additional peripherals....

we want to design the power supply for the board....

I am new to the power supply design.....i don't have any support in this regard....

i have seen the electrical specs in the datasheets, in that i have seen different types of currents like standby current, quiecent current, ICC, other different currnets.....and different type of chips is having different types of electrical specs..like memories , Buffers,GATES HAVE DIFFERENT specs......

i need guidence in that ...any online tutorials.....or How to proceed in this respect.....any recommended books to read
thanks in advance...
Check out the Analog devices, TI and Linear Technology web sites. Both TI
and Linear have their own version of Spice aimed at helping pick out their
parts which give the best power supply designs.

The main thing is to estimate worst case loads and then add 15 to 20% to
your own specs. If you find something that meets your spec, chances are
it will work nicely. If it is right at what you need chances are you'll
have weird problems on rare occasions - a major pain to debug.

If you can build a prototype and measure the currents directly that's even
better. Usually you don't have that kind of time though. I will estimate
my currents and multiply by 2 on a first spin just to make sure things
work. If the managers can deal with the cost - it's great because when
they demand more features and devices I don't have to change the supplies.

There is a lot out there in books too. Check all the web sites of
companies that build power supply parts. Many give their books away so
you'll design with their parts. You can get some good solid supplies
going at the best price/performance in pretty short order.

Good luck!

Patience, persistence, truth,
Dr. mike

On Wed, 5 Aug 2009, m...@yahoo.co.in wrote:

> HI!
> I don't know i can ask this question or not here....
>
> Actually we have a design based on BF532 which contains USB,Ethernet,VIDEO, audio and other additional peripherals....
>
> we want to design the power supply for the board....
>
> I am new to the power supply design.....i don't have any support in this regard....
>
> i have seen the electrical specs in the datasheets, in that i have seen different types of currents like standby current, quiecent current, ICC, other different currnets.....and different type of chips is having different types of electrical specs..like memories , Buffers,GATES HAVE DIFFERENT specs......
>
> i need guidence in that ...any online tutorials.....or How to proceed in this respect.....any recommended books to read
> thanks in advance...
Firstly, you should read these application notes:

EE-229: Estimating Power for ADSP-BF531/BF532/BF533 Blackfin Processors
http://www.analog.com/static/imported-files/application_notes/EE229v04.pdf

EE-228: Switching Regulator Design Considerations for ADSP-BF533 Blackfin Processors
http://www.analog.com/static/imported-files/application_notes/36488136541085EE228v01.pdf

and then this one:
EE-334: Using Blackfin® Processor Hibernate State for Low Standby Power
http://www.analog.com/static/imported-files/application_notes/EE-334_Rev1.pdf

These documents describe power consumption of the processor. The power calculation for the other circuitry (Memory, interface chips) is simpler - you should take maximum current in active state under the worst conditions for each of the power supplies and add some safety margin as Mike suggested.

Also it is wise to take a look at the power circuitry of BF533 EZ-KIT Lite (it is available for download at ADI website).

--
Alexander

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