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TPS61376: Calculation of the compensation network

Part Number: TPS61376
Other Parts Discussed in Thread: TPS61033, TPS60133

Dear,

I am working on a design and was wondering how I can easily calculate the compensation network? Is there some tool for this? Or is there a simulator for this? 

The design is to boost a battery voltage between 3V to 4.2V to 5V with 2A. 

Kind regards

  • Hi Dieter,

    Thank you for reaching out. Unfortunately, there is no published tool for TPS61376 to calculate the compensation network.

    Please provide detailed output capacitor information(effective capacitance and ESR of each paralleled capacitor, or part number) so that we can calculate the compensation parameter for you for reference. Does 2A refer to output current?

    Why do you choose the TPS61376 for your design despite we have some low voltage boost converters? Can you provide more information about your application? So that we can provide better support or recommend more suitable device.

    Regards,

    Mulin

  • Hi,

    Thank you for your response. 

    I found the TPS61376 interesting because of the 4.5A output and the possibility to have a true disconnection between input and output during EN shutdown. It also works from 2.8V. 

    In the application we charge a battery with a solar panel, this voltage needs to be boost to 5V. The 5V gets used to power the rest of our application. Is there a solution that would be better for this application? 

    The current capacitor used are: murata GRT31CR6YA106KE01K 3times, and maybe 1x vishay 293D106X0025C2TE3

    Kind regards,

    Dieter

  • Hi Dieter,

    1. 5V with 2A means output 5V2A, right? Maximum input current of TPS61376 is 3A and thus it can not support 5V2A output when Vin=3V. 4,5A refers to inductor peak current limit and it does not refer to output current.

    2. With your requirement: Vin:3V-4.2V, Vout:5V, Iout:2A, true disconnection, we recommend the TPS61033. It is fully integrated and internal compensated, so there is no need to design compensation parameters. It has 5.5A valley current limit and thus can support 2A output(5.5A also refers to inductor current, not output current).

    Please kindly let me know if you have any concern or questions.

    Regards,

    Mulin

  • Hi Mulin,

    Thanks for your response. You are right, the TPS61033 would be better. 

    What is the maximum current I can get from the TPS61033? If I am not mistaken I didn't see any way of setting the current limit. 

    Kind regards

  • Hi Dieter,

    As you can see in chap 7.5, the typical valley current limit is 5.5A and minimum 4.7A. Use 4.7A and 90% efficiency to calculate, the TPS60133 can output at least:

    Iout=Vin*Iin*eff/Vout=3*4.7*0.9/5=2.538A

    Actually, the maximum output current will be sightly larger than this value because average input current is larger than valley current.

    Iin_avg=Ivalley+0.5ΔiL

    Also, if Vin increase to 4.2V, the output current will increase.

    The 5.5A(typical) valley current limit is fixed. Do you have some special requirement for current limit setting?

    Regards,

    Mulin

  • Hi Mulin,

    The application is powered by a battery. The maximum discharge current of the battery is 3A.But since we don't need a constant flow of 2A this shouldn't be a problem.

    Thank you for the information.

    Kind regards