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TPS62736, TPS62743, TPS63031 current problem

Other Parts Discussed in Thread: TPS62736, TPS62743, TPS63031, PMP9753, TPS82740A, TPS63051, TPS61291


I want to use TPS62736, TPS62743 Buck and TPS63031 Buck-Boost converters in my designs. But i have some concern:

I need regulated voltages for my CPLD that draw in all cases less than 1 mA and I want to feed my converter with a battery that can supply max 5 mA. Therefore this current limit is enough to turn on the converters?

Secondly is there any way to limit converters input current to protect my battery? 



  • What sort of battery do you have and what output voltages do you need? This sort of configuration may be necessary:
  • Thank you vey much Mr. Chris for your quick answer.
    I want to use them to produce 1.8 and 3.3 V. My battery specs almost same as used in PMP9753. Therefore I want to use TPS62736 or TPS62743 for 1.8 V and TPS63031 for 3.3 V and all these voltages will drive CPLD.

  • Yes, you can use TPS62743 or TPS82740A for the 1.8V directly from your battery. I recommend some additional capacitance in parallel with it to provide currents for start-up, etc.

    Do you have any peak currents in your system, such as for a radio?

    What is the minimum load on the 3.3V rail? The TPS63051 is likely the easiest option to get there, but it will draw too much current at very light loads (<10uA). A boost + bypass converter such as TPS61291 may be a better option if the CPLD can tolerate the higher battery voltages.
  • I have only inrush current while CPLD startup but it can be easily handled by bulk capacitors and there is not any peak currents.
    Thank you very much for your suggestions but most of the time converter will operate under very light loads and CPLD can operate with 3,3 V+- 10%.