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TPS62110: startup time estimation II

Kazuhiko Hirano
Genius 15118 points
Part Number: TPS62110

Hello,

 

My customer would like to use TPS62110 for the following four cases at Vin=12V, Lout=6.8uH and Cout=94uF(47uF x2).

  1. Vout=7V/0.19A

  2. Vout=5V/0.7A

  3. Vout=5V/0.1A

  4. Vout=3.3V/0.5A

 

Could you estimate typical start-up time for those four cases by simulation, please?

 

Best regards,

 

K.Hirano

  • 0
    TI__Guru**** 191445 points

    Hirano-san,

    As you note:

    The TPS6211x has an internal soft-start circuit that limits the inrush current during start-up. This prevents possible voltage drops of the input voltage when a battery or a high-impedance power source is connected to the input of the TPS6211x devices. 

    The soft start is implemented as a digital circuit increasing the switch current in steps of 300 mA, 600 mA, and 1200 mA for 250 μs each. Then, the switch current limit is set to 2.4 A typical. Therefore, the start-up time depends on the output capacitor and load current. Typical start-up time with a 22-μF output capacitor and 800- mA load current is 1 ms. 

    It takes a fair amount of time to run simulations.  Let me see if I can get to it in the next couple days.

  • 0 in reply to JohnTucker
    TI__Guru**** 191445 points

    Hirano-san,

    The sim results are as follows:

    1. Vout=7V/0.19A = 883 usec

    2. Vout=5V/0.7A = 903 usec

    3. Vout=5V/0.1A = 829 usec

    4. Vout=3.3V/0.5A = 800 usec