• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 31 subscribers
  • Views 643 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

IWR1642BOOST: The IWR1642BOOST produce a sound

user5051058
Prodigy 80 points
Part Number: IWR1642BOOST
Other Parts Discussed in Thread: IWR1642, , LP87524B-Q1

Hello team:

When the IWR1642BOOST run zhe demo program,the current of radar system(IWR1642) exist a

stable ripple,the frequency is about 2KHz. This caused the 4-ch DCDC(LP87524B-Q1) part

producing a sound. There is a same problem on my radar board using IWR1642. How can we

fix it?

  • 0
    Prodigy 80 points
    Thanks a lot.

    morgan. 2107.12.12
  • 0 in reply to user5051058
    TI__Mastermind 37500 points

    Hello Morgan,

    There is more information about the LP87524B and other DC to DC converters in the Power Management E2E links.  The reference here is to the 

    bypass ceramic capacitors, and their mounting.

    ' e2e.ti.com/.../how-to-reduce-acoustic-noise-of-mlccs-in-power-applications  '

    Regards,

    Joe Quintal

  • 0 in reply to Radio-Joe
    Prodigy 80 points
    Hello Joe:

    The DCDC output voltage is table,but the output current is periotic change.The iwr1642 load current cause the DCDC output current. So the inductor maybe the component causing the sound. I know this problem is thorny, otherwise it was already soved on the IWR1642BOOST，and we tried a lot of ways to remove the sound,including the capacitor、inductor、IC、diode,and adding the output current buffer,and adding inductor to smooth the current.
    We can just discuss how to sove it.


    Thanks,
    Morgan
  • 0 in reply to user5051058
    TI__Mastermind 37500 points
    Hello

    Please consult the Power Management forum, article recommended.
    ' e2e.ti.com/.../how-to-reduce-acoustic-noise-of-mlccs-in-power-applications '

    A DCtoDC Converter will have switching noise normally. You have lightly loaded 3.3v. You have loading based on the MSS, SOC peripherals and DSP, so the 1.2v rail has a larger load. The 1.8v and 2.3v rails have dynamic load, when the radar RF is turned on (active chirp).

    The 1.8v and 2.3v have LDOs to reduce the voltage to (1.8v to LDO)1.3v and (2.3v to LDO)1.8v. The article mentioned discusses how to select
    different bypass capacitor physical parts to reduce noise, ' e2e.ti.com/.../how-to-reduce-acoustic-noise-of-mlccs-in-power-applications ',
    this applies to the DC to DC Converter 5v input, and the rail output capacitors.

    The DCto DC converter could also have a similar behavior.

    These power supply discussions, require a power management application engineer, past this description, in the power management forum.

    Please ask the PMIC or output bypass capacitor questions, responding to '' e2e.ti.com/.../how-to-reduce-acoustic-noise-of-mlccs-in-power-applications '.

    Regards,
    Joe Quintal