• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 384 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

BQ76952EVM: How FUSE different then CHG and DCHG?

Naveen Dagar1
Prodigy 40 points
Part Number: BQ76952EVM
Other Parts Discussed in Thread: BQ76952, BQ7718
  • Refer attached datasheet BQ76952 page no-26 ,
  • Is there any MosFET available in battery monitor section ?
  • Why fuse is required?,
  • How FUSE different then CHG and DCHG? 
  • What Type fuse – Is P-Chanel MosFET can be used ? or suggest.

 

  • Refer attached datasheet BQ76952 page no-196 ,
  • Why addition over voltage protection circuit-BQ7718 required ?
  • Can we manage over voltage protection with BQ76952 ? kindly suggest

 

  • 0
    TI__Guru 54715 points

    Hi Naveen,

    Page 26 of the data sheet is the functional block diagram.

    • Is there any MosFET available in battery monitor section ?

    The internal structure will have various semiconductor components.  There are no integrated MOSFETs to carry and switch battery current internal to the IC.

    • Why fuse is required?,

    A fuse may be desired or required by the battery system requirement as a backup or permanent protection system to the reversable FET switching.

    • How FUSE different then CHG and DCHG? 

    See the data sheet section 7.3.4 for description of the FET vs fuse protection. https://www.ti.com/document-viewer/BQ76952/datasheet/integrated-protection-subsystem-t5055361-5#t5055361-5 The FUSE output can sense the activation of an external protector device or drive an output to activate a battery fuse. CHG is a FET driver for a high-side N-ch power FET to control battery current in the topology shown in the circuit diagrams.  DCHG is a digital output which can be set to represent the state of CHG if configured appropriately, it could signal a MCU or FET driver.

    • What Type fuse – Is P-Chanel MosFET can be used ? or suggest.

    The typical battery fuse is a 3 terminal fuse which can be opened by a signal in addition to excess current.  See Dexerials, Schott or other manufacturers of battery fuses. Check with the vendors on requirements to operate their fuses.  The FUSE output of the BQ76952 is not configured to operate a P-channel MOSFET, you may be able to design a suitable circuit.

    Page 196 is the FET and secondary protection figure of the EVM schematic.

    • Why addition over voltage protection circuit-BQ7718 required ?

    Some system requirements will specify an independent monitor of the cell voltage to disable the battery.  The BQ7718 provides a capability independent of the BQ76952.

    • Can we manage over voltage protection with BQ76952 ? kindly suggest

    Yes, the BQ76952 can be configured to provide overvoltage protection using the CHG FET output (or DCHG).  If configured for secondary protection it can have a permanent fail condition and set the FUSE output to blow a battery fuse. That may or may not be suitable for your system requirement.