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TPS61094: How to properly calculate supercap parameters

Part Number: TPS61094

Hey Boost Converter team,

I have a customer evaluating the TPS61094 for a new project and we were hoping you could help provide guidance on how to properly calculate the supercap parameters; please see a summary of our inquiry below!

We have a few technical questions regarding ap note SLVAF41A, it is not clear to us on page 10 on the end of the paragraph it says “The power consumption of one transmission is about 4J”. According to our calculations of 3.3V, 250ma and 250ms the energy required should be 0.2J, not sure where the 4J are coming from, using this value is how you find the capacitance of the required super capacitor. 

We calculated a 0.22F Supercap for our system but would like confirmation from your team that this is correct. Please let us know what additional info you need to provide feedback and help confirm the design calculations.

Best regards,

Matt Calvo

  • Hi Matt,

    3.3V, 250mA, 250ms is only for one pulse.

    But there generally would be several pulses current during transmitting, it depends the communication module you used, the data you need to transmit, and transport protocol, etc... You can take the figure below as a reference.


    The 250mA, 250ms or 4J in this app note are just an example.

    Customer could test the real load current waveform during their transmitting, then get the total energy consumption during a complete data transmission process.



  • Thanks for the reply Nathan! I'll pass this along to the customer and will have them comment back here directly with any follow-up questions they may have.


  • Ok, fine. Let me know if there is any other question.



  • Thanks Nathan, this is Antonio Fematt the person in charge of this project, at this moment we do not have more questions, we already have a preliminary design using TPS61094 which we intend to test next week, if we find any problem  I will get back to you through here.