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Power SPA3102 with 12V?

Hi.  I've got an application where I'd like to power SPA3102 ATAs from an existing 12V DC power supply.  Looking inside the unit, I see it uses an AP1513 switching regulator that has an input range of 3.6 to 18V, so it seems conceivable that 12V would be fine.  However, I'm not sure about the support components.

Does anyone know the acceptable input voltage range for the SPA3102?  Or know where to find out?

Thanks,

  Adrian.

3 REPLIES

Power SPA3102 with 12V?

These are notes reported on original data sheet:

Power supply

Power consumption: 5W

Switching type (100-240V) automatic

Power adapter: 100-240V, 50-60 Hz (26-34 VA) AC input

DC input voltage: +5V DC at 2.0A max

Different values can damage the SPA.

You can realize a simple circuit with LM 7805 to get 5v from 12v.

Regards.

New Member

Power SPA3102 with 12V?

Thanks for your response Daniele.  I understand that the datasheet specifies +5V, but in reality it's never as simple as specify a single voltage (that is, no power supply will output an exact voltage, especially under varying load conditions).  All device can accept a range of voltages, some much smaller than others.

Thanks also for your suggestion of the 7805, but I was actually thinking of using a 12 to 5V DC-DC converter (like this one:  http://www.current-logic.com/shop/index.php?main_page=product_info&cPath=4&products_id=204).  I discounted a linear regulator such as the 7805 because it will dissipate a whole bunch of power/heat.  Dropping 7V at 2A peak is 14W!  Also, the 7805 in TO-220 packages are usually rated at only 1.5A, and going to the TO-3 package with appropriate heat sinking is a real pain to deal with (and are quite physically bulky).

But either way, seeing as the SPA3102 already has a switching regulator built it, it seems superfluous to use an external regulator.

I guess what I'm really asking is:  Where can I find the "absolute maximum" ratings for the SPA3102?  This level of detail doesn't seem to be covered on the standard datasheet.

Green

Power SPA3102 with 12V?

Hi,

From the data sheet

http://www.cisco.com/en/US/prod/collateral/vpndevc/ps6918/ps9692/ps9944/ps9946/data_sheet_c78-502105.html

Power supply

• DC input voltage: +5V DC at 2.0A max

• Power consumption: 5W

• Switching type (100-240V) automatic

• Power adapter: 100-240V, 50-60 Hz (26-34 VA) AC input


HTH

Alex

Regards, Alex. Please rate useful posts.
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