• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 64 subscribers
  • Views 695 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.

LM25118: LM25118 Related Detail Reqired

Shubham patil
Intellectual 520 points
Part Number: LM25118
Other Parts Discussed in Thread: LM5155, LM5115, LM2775

Hii Team .

Please find attached the Image for review.

Scheme 1:  

Input voltage (Battery charger output ): 3.2V to 4.2V

Output voltage: 4V

Output current: 6A

  • 0
    TI__Guru* 76035 points

    Hi Shubham,

    Thank you for designing with the LM25118.  You may not be able to use the LM25118 in such way because it requires at least 5V input to start up.  Once it starts up, the input voltage can drop to 3V.  This is mentioned in the datasheet. 

    For your 3.2 to 4V input, you may consider to add a small boost to generate 10V bias rail to feed into the VCC pin, then the LM25118 can operate and support your 6A load.

    You may also consider the LM5115 in a boost to produce 4V.  Also your 4.2V seems being higher than 4Vout, the LM5155 uses a rectifier diode, which makes the equivalent Vout = VF+Vout = ~4.4V (Schottky), and you should be able to just use a boost to get the 4Vout regulation.

    Thanks,

    Youhao Xi, Applications Engineering

  • 0 in reply to Youhao Xi
    Intellectual 520 points

    Hii Youhao,

    Thanks ,

    Can you plz give me the Buck Boost part for given application.

    Input voltage (Battery charger output ): 3.2V to 4.2V

    Output voltage: 4V

    Output current: 6A

    The part is required low cost .

    Thanks,

    Shubham 

     

  • 0 in reply to Shubham patil
    Intellectual 520 points

    Hii Youhao,

    This charge pump in our case 

  • 0 in reply to Shubham patil
    TI__Guru* 76035 points

    This charge pump concept does not work because the LM25118 may not power up to switch and drive the charge pump in the first place.   Please consider an independent charge pump device like LM2775 to produce 5V for the VCC pin from your 3.2V to 4.2V input line. 

    Thanks,

    Youhao