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LP5922: Recommendation fro High current and high noise attenuation LDO

d_zero
Genius 4815 points
Part Number: LP5922
Other Parts Discussed in Thread: TPS7A91

Dear *

I'm looking for LDO that has:

-> min 1A load

-> High noise attenuation up to 1MHz

-> in smallest package that there is  (eg. 3mm x3mm)

Is there a better choice that LP5922?

Best Regards.

  • 0
    TI__Guru 50190 points
    HI D-Zero,

    Have a look at our newest low noise 1A LDO the www.ti.com/.../tps7a91

    This has really high PSRR and very low output noise and comes in a 3x3 package!

    Let me know what you think.

    Regards,
  • 0 in reply to JCHK
    Genius 4815 points
    Dear John,

    can be the TPS7A91 be compared to LT3080 in terms of Output current and the noise filtering to 1MHz?

    can I have 2000uF on the output of TPS7A91 like on the LT3080?

    Best Regards.
  • 0 in reply to d_zero
    TI__Guru 50190 points

    Hi d-zero,

    As for noise, we are ~1/10th of the LT3080 noise from 10-100KHz. We would have to compare the two out to 1MHz but the lower frequency noise is the hardest to attenuate.

    With respect to PSRR, assuming a single ended supply, as you can see from the below. the LT device has ~30dB of attenuation at 200Khz and it continues to fall from there. The TPS7A91 (under similar not the same) conditions has over 55dB of attenuation (3Vin - 1.2VOUT = 1.8VDO vs LT's 2.0VDO)

    Here is the comparison over current but keep in mind this chart is using only 500mVDO:

    Is this what you were looking for?

    Regards,

  • 0 in reply to JCHK
    Genius 4815 points

    Dear John,

    thanks for the quick replay.

    if I have to filter the noise that comes from SMPS that is working form 900kHz to 1.1MHz, than I will say that the TI has better PSRR performance on that frequency, TI has around 50dBm and Linear 15dBm, is this correct?

    What will happen to the PSRR if the Vldo= 200mV -> because I plan to use the LDO Vin 3.5V to LDO Vout =3.3V?


    And there is no problem if I connect 12*100uF on the output of TPS7A91?

    Best Regards.