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UCC2813-0-Q1: extend soft start time

Part Number: UCC2813-0-Q1
Other Parts Discussed in Thread: UCC28C42


Is there any way to increase the soft start time to limit the inrush current? According to the d/s, the soft time maximum is 10ms but it's not enough.



  • Hi Dongbao,

    Soft-start is performed within the UCCx813-x devices by clamping the E/A amplifier output (COMP) to the voltage on an internal soft-start capacitor (Css). So we can't change the charging current or Css to change the SS time.
    But I think you can refer the recommended soft start implementation in the UCC28C42 datasheet as attached, adding another external soft start circuit to increase the soft start time, I have tested it in the simulation.