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LP2992: About equation for Turn-on time

Satoshi
Guru 19495 points
Part Number: LP2992
Other Parts Discussed in Thread: TLV713P, TPS799

Please let me know about equation for turn on time of LP2992.

I think that turnon time is depend on below spec and bypass capacitor, is there the other important spec? 

⇒Vin: 3.3V, Vout: 2.5V, Iout: 100mA

※Customer hope that Turn on time is less than 10ms.

Best regards,

Satoshi

  • 0
    TI__Guru 55940 points
    Hi Satoshi,

    LP2992 was originally released by National Semiconductor in 2001. Due to the age and acquisition we no longer have documents available to provide a startup equation.

    Your customer conditions are similar to the conditions used for Figures 30 to 33. From these Figures it is clear that the bypass capacitor is the biggest factor in startup time.

    Which package are you using? Perhaps we have another LDO that fits your customer's application requirements.

    Very Respectfully,
    Ryan
  • 0 in reply to Ryan Eslinger
    Guru 19495 points
    Ryan-san

    Thank you for quick reply,

    Package and full device number is below.
    ⇒LP2992AIM5-2.5/NOPB

    Best regards,
    Satoshi
  • 0 in reply to Satoshi
    TI__Guru 55940 points
    Hi Satoshi-san,

    LP2992 uses the most common SOT-23 pinout. As such we have many LDOs that meet your currently stated requirements. Do you have any further application requirements to help better select the right LDO for your application?

    To start with take a look at TPS799 and TLV713P.

    Very Respectfully,
    Ryan
  • 0 in reply to Ryan Eslinger
    Guru 19495 points
    Ryan-san

    Thank you for information.

    Application is FPGA:MAX 10 VCCA power supply.
    (2.5Vout, 30mA_max)
    Start up time is required less than 10ms, customer is hope to specified this time on LDO.

    Best regards,
    Satoshi