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  • TI Thinks Resolved

BQ2947: bq294

Intellectual 255 points

Replies: 9

Views: 657

Part Number: BQ2947

Hi Guys,

Does this IC have any place in the following diagram that can work at 9KHz or faster ? Our end customer is asking if this device generates a 9khz above frequency by active circuit in bq2947.

  • Hi Shane,
    Yes the bq2947 uses digital circuitry internally and may have clocks above 9 kHz. The capacitors shown should be placed close to the device as indicated in the data sheet layout section.

    "Please click "This resolved my issue" button if this post answers your question"

    TI provides design resources and design advice (including technical, schematic, code and/or system review) “as is” and with all faults.  All information in this or related correspondence is provided subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • In reply to WM5295:

    Hi Guys,

    Can we say YES that has an active circuit with 9Khz or more?

  • In reply to MF Lo:

    Hi MF,
    Yes

    "Please click "This resolved my issue" button if this post answers your question"

    TI provides design resources and design advice (including technical, schematic, code and/or system review) “as is” and with all faults.  All information in this or related correspondence is provided subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • In reply to WM5295:

    Hi,
    Could you indicate and specify which circuit it is in it & how much frequency exactly it is ( ?? kHz )
  • In reply to MF Lo:

    Hi MF,
    No, I don't have details. It is digital and there is 1 VSS pin. It should be considered between VDD and VSS. Follow the filtering and bypass recommendations in the data sheet.

    "Please click "This resolved my issue" button if this post answers your question"

    TI provides design resources and design advice (including technical, schematic, code and/or system review) “as is” and with all faults.  All information in this or related correspondence is provided subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • In reply to WM5295:

    Hi,

    Sorry to ask you again.

    We have question from Japanese customer, they still want to know the frequency in bq2947.

    Because they will do FCC/CE certification and they concern the frequency will affect end of product.

    According to this concern, could you please help to ask circuitry design center what frequency it is.

    Thanks again.

  • In reply to MF Lo:

    Hi MF,
    4.5kHz.

    "Please click "This resolved my issue" button if this post answers your question"

    TI provides design resources and design advice (including technical, schematic, code and/or system review) “as is” and with all faults.  All information in this or related correspondence is provided subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • In reply to WM5295:

    Hi,
    I am confused about the frequency, before you correct it to 4.5KHz, you replied yes it would be 9KHz or more.
    Could you please help to clarify the difference between 9K and 4.5KHz?
    Since it is a major concern asked by our customer, a more detailed is much appreciated.
    Thanks you very much.
  • In reply to MF Lo:

    Hi MF,
    Without having the design published, expect the 4.5kHz is a clock. At 4.5kHz the fundamental is below the 9kHz, but expect it is divided from a higher frequency. Dividing by 2 would be 9kHz. Dividing by other even numbers perhaps up to 20 would give 90kHz. Lower frequencies should be expected to be a clock or square wave with significant odd harmonics. 4.5k, 13.5k, 22.5k, 31.5k... also 9k, 27k, 45k, 63k... easily check frequencies up to a few hundred kHz.
    If the test is to look for emissions, certainly set up to look in the 9kHz range and above. If the test is to try to disrupt the part, use the standard test frequencies in that band or measure the emission and try to drive those frequencies into the system according to the test method.

    "Please click "This resolved my issue" button if this post answers your question"

    TI provides design resources and design advice (including technical, schematic, code and/or system review) “as is” and with all faults.  All information in this or related correspondence is provided subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

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