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TPS2491: Information about part obsolescence and possible alternatives

Carlos Silva85
Expert 4915 points
Part Number: TPS2491
Other Parts Discussed in Thread: TPS2662, TPS2660, LM5069

Hi Team,

One of my customers is looking for a hotswap controller with power limiting capability on a new design with a 10 year product life.

They have identified the TPS2491 as a possible solution, but are concerned the part is on the market for a while and would be willing to consider more recent solutions. The requirements are an absolute max input voltage of 51V at a current of 2 Amps peak (or 60W). Ideally Internal Mosfet, but external can also be considered.

Any recommendations on suitable parts?

  • 0
    TI__Guru** 105361 points
    Hi Carlos,

    Please look at integrated FET solutions TPS2662, TPS2660 and let us know if you have any questions. These are recently released parts.

    Best Regards,
    Rakesh
  • 0 in reply to Rakesh
    TI__Expert 4915 points

    Thank you.

    Couple questions:

    Those seem to be e-fuses, rather than hot swap controllers; are they a suitable alternative?

    The TPS2491 is functionality sound, but the current limit accuracy is quite imprecise, which makes it unsuitable for the application. Would the LM5069 be a better choice, on this respect?

  • 0 in reply to Carlos Silva85
    TI__Guru** 105361 points
    Hi Carlos,

    Yes. eFuses are nothing but integrated hot-swap solutions and offers better current limit accuracy.

    Best Regards,
    Rakesh
  • 0 in reply to Rakesh
    TI__Expert 4915 points

    Hi Rakesh,

    I've had feedback on using the TPS2660 family, but it seems these devices to not handle the required power dissipation (circa 60W) needed during load power up. The requirement is to be able to withstand this with ambient temperatures up to 75C (A potential difference of 30V @ 2A while the load capacitors are charged).

    Looking at our application report SLVAE07, I was wondering if current sharing would be viable and whenever we may have some test data. The report addresses external mosfets. Do we have any data on how well current sharing would work if I were to use two TPS2660 with the current limit on each set to 1/2 of the rated load?

  • 0 in reply to Carlos Silva85
    TI__Guru** 105361 points
    Hi Carlos,

    Initial power dissipation while the load capacitors are charged can be adjusted by configuring the output voltage ramp rate using CdVdT capacitor on dVdT pin for TPS2660.
    CdVdT capacitor helps in limiting inrush current and hence the power dissipation across the device.
    Please refer to Figure 51 in the TPS2660 datasheet.

    Please fill in your system parameters in the design calculator at www.ti.com/.../toolssoftware and check.

    Best Regards,
    Rakesh
  • 0 in reply to Rakesh
    TI__Expert 4915 points

    Unfortunately the upstream DC-DC converter draws a constant 2A on top of the capacitor charging and this cannot be delayed. So the solution would be to partially increase the current during startup to some 3A.

    Hence my question remains, do we have test data for the ability of running multiple modules in parallel and how well would they share current? 

  • 0 in reply to Carlos Silva85
    TI__Guru** 105361 points
    Hi Carlos,

    Yes, you can use multiple devices in parallel for higher current application.
    Please refer to the app note at the following link for more information on paralleling of eFuses. www.ti.com/.../slva836.pdf

    Best Regards,
    Rakesh