• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 63 subscribers
  • Views 710 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

PTH08080 or PTH series polarity, negative capabilty?

Owen Wetzel
Prodigy 130 points
Other Parts Discussed in Thread: PTN04050A

Hello TI Dudes and company,

I'm a bit psyched out by this PTH series of DC-DC converters, dig? More specifically the PTH08080, but I could probably use others in the that series too, it depends on the answer I get here. what I can't seem to figure out is: can they work on a negative voltage rail also? I mean, the datasheet just mentions operation in the positive side of V, but can it work, say, in a -V to -V conversion scheme? I'd really like to know becuase it's gonna suck if I have to use something bigger these little fellas. they just fit really nicely on my otherwise totally awesome layout. I dig their minimalist (ic?) footprint and they they dish out more amps than my solar-powered arc welder, which is wicked.

thanks

├╩╔╚┤

  • 0
    TI__Mastermind 38230 points

    The PTH08080 cannot be reconfigured to -X to -X volts, Negative regulator. We have no other non-isolated modules which can be configured for -Vin to -Vout.

    We have two design series  for conversion to:

    (+) input voltage to (-) output voltage.

    PTN78000WAx +12Vinput voltage  to -2.5V to -9V up to 9W output power

    PTN04050A +2.9V to +7V input voltage and -3.3V to-15V at 6W output power .

    Possible isolated converters for (-) vin  to regulated (-) vout DCR01 series (1W) and DCR02 series (2W)

    If the maximum ouptut power is 1W to 2W , and the input voltage +or - (5, 12, or 15,) and output voltage is 5 or or 3.3v regulated, then the isolated converters can be configured for (-) vin to (-) Vout .

    Regards

    To

    tguerin@ti.com

  • 0 in reply to Tom Guerin
    Prodigy 130 points

    Thank you for your informative reply. there is one thing I forgot to mention which actually ruins it totally, and that's the fact that I need 5.2V. The one you suggested I use does not have a 5.2V model, nor does it have an adjust or TRIM pin. Too bad, I really liked that package. It would done nicely.

     

    I still find it hard to believe that there arent' any more solutions to be offered. All I need is -5.2V from -12V under 2W.

     

     

    In any case thank you for answering my original question.

     

    OW

  • 0 in reply to Tom Guerin
    TI__Mastermind 38230 points

    Hi Owen:

    I  also found a 1.5A , older generation 3 pin version , 1" x1"  which has a fixed -5.2Vout with -12Vin , input range is from -9.2 to -30Vin. There is also very limited availability from from Digi-key. The maximum reflow temperature is 215°C. There are no samples available for this older 3 pin module.

    http://focus.ti.com/docs/prod/folders/print/pt79sr152.html

    Regards

    Tom