• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 65 subscribers
  • Views 580 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.

lm2611

ou gareth
Intellectual 340 points
Other Parts Discussed in Thread: LM2611

Hi

How to calculate LM2611 output voltage?

  • 0
    TI__Mastermind 19891 points

    Hello Ou, 

    The datasheet seems to suggests changing the bottom feedback resistor and keeping the top at 29.4k.

    So then, Rfb_bot = Rfb_top x Vfb  /  (Vout - Vfb)

    Where:

    Rfb_bot = Rfb2 in the schematic

    Rfb_top = Rfb1 in the schematic = 29.4k

    Vfb = -1.23V

    Vout = the output voltage you want (i.e. -5V).

    The maximum output current capability of the converter will change with the output voltage level. See Figure 23 on page 11, Figure 25 on page 12, and Figure 27 on page 13 of the datasheet.

    Regards, 

    Denislav

  • 0 in reply to Denislav Petkov
    Prodigy 10 points

    Hi,

    The circuits shown on the datasheet show different inductor sizes for different input voltages.  Sorry if this is a basic question, but is it possible to design a circuit that takes a variable input voltage (within the specified range) and output a variable voltage?


    Thanks,

    Ali

  • 0 in reply to Ali Etezadkhah
    TI__Genius 15810 points

    Hello Ali,

    You could design a circuit for variable input range to regulate to a fixed output. Please go wit the datasheet suggestion for the inductor values.

    To create a design for variable output, you'd need some kind of a digital feedback like a DAC. A DAC could either sink or source current in to the feedback network to change VOut while FB is kept regulated. 

    Regards,
    Akshay