FPGA Central

Hi ,
we are designing a Communication system (Microprocessor , VHF Transceiver , Clock
circuitry , digital logic & etc).

We are seeing some peak currents at power on for few tens of microsec.We are seeing
about 900 mA of current at the power on before it settles to normal levels.

*where as in normal operation we are seeing about 200 mA which is correct.

Pls see if you any inputs to mitigate this effect apart from using some Inductors
in the input supply path.

regards
Sunil bharadwaz.




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Hi Sunil,
Perhaps you are alluding to the concept called Inrush current, issue
associated with any electronic designs
Inrush current or input surge current refers to the maximum, instantaneous
input
current drawn by any Electronic design.This is because the capacitor offer
very less impedance when
immediately after the input voltage is connected.

There are several component options available to limit inrush current .The
two most common alternatives are the use of NTC (Negative Temperature
Coefficient) thermistors or various forms of active circuits.

Thank You,
Aravind

On Thu, Mar 12, 2009 at 10:54 AM, sunil bharadwaz <sunil_bharadwaz (AT) yahoo (DOT) com
> wrote:

> Hi ,
> we are designing a Communication system (Microprocessor , VHF Transceiver ,
> Clock
> circuitry , digital logic & etc).
>
> We are seeing some peak currents at power on for few tens of microsec.We
> are seeing
> about 900 mA of current at the power on before it settles to normal levels.
>
> where as in normal operation we are seeing about 200 mA which is correct.
>
> Pls see if you any inputs to mitigate this effect apart from using some
> Inductors
> in the input supply path.
>
> regards
> Sunil bharadwaz.
>
>
>
>
> ------------------------------------------------------------------
> To unsubscribe from si-list:
> si-list-request (AT) freelists (DOT) org with 'unsubscribe' in the Subject field
>
> or to administer your membership from a web page, go to:
> http://www.freelists.org/webpage/si-list
>
> For help:
> si-list-request (AT) freelists (DOT) org with 'help' in the Subject field
>
>
> List technical documents are available at:
> http://www.si-list.net
>
> List archives are viewable at:
> http://www.freelists.org/archives/si-list
> or at our remote archives:
> http://groups.yahoo.com/group/si-list/messages
> Old (prior to June 6, 2001) list archives are viewable at:
> http://www.qsl.net/wb6tpu
>
>
>


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