• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 448 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.

LM5176: LM5176 Startup mode during SS

Wei-Hao Chen (TW-FAE)
Expert 3260 points
Part Number: LM5176
Other Parts Discussed in Thread: LM5175

Hi Support team,

My customer is having a question regarding the mode of operation during SS. Which mode does LM5176 work in during the SS? And how does it determine to transit mode during the SS (if it works in multi-mode)?

Second question, LM5175 supports DCM mode. Does LM5176 also support DCM by shorting the MODE pin to ground or set mode resistor to 49.9kohm?

Many thanks.

Best Regards

Wei-Hao

  • 0
    TI__Guru* 78440 points
    Hi Wei-hao,

    The LM5176's operating mode is determined by sensing the input and output voltage differences. When Vin > Vout+1V, it operates in buck. When Vin < Vout -1V, it operates in boost. When Vin is within Vout +/-1V, it operates in buck-boosts. So during startup, if the output voltage is not prebiased, it will operated in buck and Vout will rise, and the mode can change by the above criteria.

    Regarding the DCM, the LM5176 does not support DCM because the boost sync FET cannot be guaranteed to turn on during in some case when DCM is selected. This is one of the differences between the LM5175 and LM5176,

    Thanks,
    Youhao Xi
    System and Applications Engineering, APP-BMC-BCS Product Line