OSD32MP153C-512M-BAA OSC32_IN

This topic has 4 replies, 3 voices, and was last updated 2 years, 8 months ago by gil_he.

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- February 17, 2022 at 12:42 pm #12064
  gil_he
  Participant
  hello Neeraj,
  OSD32MP15x_RED schematic uses an external 32KHz oscillator on PC14-OSC32_IN pin.
  I know there is an internal LSI oscillator that can be used.
  In Octavo eval board (DK2) it’s stated:
  “Engineering Sample (ES) OSD32MP15x parts do not have integrated 32.768kHz oscillator. The clock needs to be fed
  externally through N1 and N2 pins. For the production OSD32MP15x parts, check the latest datasheet to determine
  the requirement of external 32.768kHz oscillator”.
  How do I know our samples have the integrated LSI inside?
  We purchased it from Mouser (package is still sealed).
  Lot Code: Q924487V. Date Code: 2035. PN: OSD32MP157C-512M-IAA.
  Thank you
  Gil
- February 21, 2022 at 9:29 am #12070
  Neeraj Dantu
  Moderator
  Gil,
  The RTC(32KHz) oscillator is not included in the production parts. You will need to add an external oscillator. Please take a look at https://octavosystems.com/docs/osd32mp15x-red-schematic-pdf/ for the latest revision of our reference design for OSD32MP1.
  Best,
  Neeraj
- February 21, 2022 at 11:23 am #12072
  gil_he
  Participant
  hello Neeraj,
  As far as I can see, a 32KHz LSI is integrated in the STM32MP153C/F.
  See stm32mp153c datasheet pages 30,151.
  Can’t it be used?
  Why do I need an external 32KHz oscillator? (32KHz LSE).
  Another question:
  The LSE is mainly used for RTC/AWU and .If I don’t require RTC support, is this oscillator required?
  thanks,
  Gil
  - This reply was modified 2 years, 9 months ago by gil_he.
  - This reply was modified 2 years, 9 months ago by gil_he.
  - February 25, 2022 at 10:12 am #12096
    Eshtaartha Basu
    Moderator
    Hello gil_he,
    External oscillators are generally more accurate and have less jitter compared to internal ones. If timing precision is not a concern, internal oscillator can be used keeping tolerances in mind.
    If RTC is not required, LSE oscillator is not necessary. You can leave its pins floating as recommending here – https://octavosystems.com/app_notes/osd32mp15x-schematic-checklist/#Reset%20and%20Clock
- March 2, 2022 at 9:32 am #12101
  gil_he
  Participant
  Got it.
  Thank you !
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