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TPS65142: Boost regulator 6-21V input, 9.2V output, max 2Q

Andrew Kling
Intellectual 2810 points
Part Number: TPS65142

Customer has started looking at TPS65142 for the requirement of: boost Regulator 6-21V input output 9.2V (+/- 100mv) 2W.

Customer Comments:

3.3V is used to derive 9 and 28V power rails. This is 2 stage conversion with poor matching in both stages.

As we apply to notebooks: we see a 2s/3s/4s Source (6-17.8 battery) to 3.3V stage >> then 3.3V to 9V and 28V stage.

This type of topology has both a Buck and a Boost – We hold that direct conversion from Battery (2S-4S) would drop a stage completely with an additional benefit of reduced 3.3V power losses/sizing.

In the short term – a discrete path looks possible and would like to discuss a modified 65142 roadmap that would use the input power more wisely. (it already uses V_bat for example – just not this section)

Would TI propose anything different?

  • 0
    TI__Expert 8010 points
    Hello Andrew,

    Not sure if I got this, you are searching for a power conversion that fits for 2s/3s/4s sources to generate 9 V and 28 V without the intermediate voltage of 3.3 V, is that correct? Why do you see concerns in using the TPS65142 for this?

    Best Regards.
    Ilona
  • 0 in reply to Ilona
    TI__Intellectual 2810 points

    Customer fed back that TPS65142 boosts from 3.3V – not V_battery which is desired.

    It does not take advantage of Vbattery drive in the backlight section to offset boost loss in the high voltage TCON driver section.

    Customer would like to get an optimal – buck boost part for 9V (discrete) and a buck part optimal for 28V to create our new low power Panel solutions.

    Looks like this falls outside of the LCD Bias team...

  • 0 in reply to Andrew Kling
    TI__Expert 8010 points

    Hello Andrew,

    What keeps you from using a resistive divider to supply the boost rail? The relations of VIN-min/V_battery-min and VIN-max/V_battery-max are almost the same. Additionally you can use a zener diode to make sure not to go beyond 6 V which is the max. rating for the input pin.

    Best Regards.
    Ilona

  • 0 in reply to Ilona
    TI__Expert 8010 points
    Hello Andrew,

    Did you find a suitable solution for your problem? It would be great if you can give us a short feedback.

    Thank you.
    Best Regards.
    Ilona
  • 0 in reply to Ilona
    TI__Intellectual 2810 points

    Customer needs an accurate (V source +/- 100mv control) and low loss conversion over several battery S topology (2,3,4 S).

    2W Zener is conceptual, Z height has impacts/limits.  They want us to provide a WideVDC solution.  Working with that team now.