• State TI Thinks Resolved
  • Locked Locked
  • Replies 7 replies
  • Answers 3 answers
  • Subscribers 63 subscribers
  • Views 432 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.

LM20343EVAL: Minimum voltage in for 4.9V 2.33A out

Isaac Porras
Prodigy 40 points
Part Number: LM20343EVAL
Other Parts Discussed in Thread: LM20343, TLV62130A

For this LM20343 Evaluation Board, what is the minimum input Voltage for a 4.9 volt output under 2.33A load?

  • 0
    TI__Prodigy 480 points
    Hi Isaac,

    I would recommend using Webench. If there is an error, Webench would tell you what is wrong. Based on your parameters, I was able to get a min Vin at 6.6V on Webench.

    However, as stated in the User guide, the evaluation board was designed to operate at a Vin of 12V, but it could work from a 4.5V to 25V (due to the voltage ratings of the capacitors). Therefore, for an evaluation board with your parameters, a Vin between 6.6V-25V should be good.
  • 0 in reply to Eric Sato31
    Prodigy 40 points
    Thanks, Webench is not letting me enter a Vin below 7V for LM20343. Is it possible to just load the Eval Board configuration automatically and edit it? I'm using a battery pack for Vin, which ranges from 8.4V-5V. I did modify the Rfb1=46.4k and Rfb2=7.32k, which seemed to give me the most power output without the inductor making a buzzing noise. With this added configuration information, is 6.6V still the lowest Vin possible? A lower Vin minim is ideal so that the battery pack can be used to its full capacity.
  • 0
    Prodigy 40 points
    Also, is this minimum voltage open circuit or closed circuit under load?
  • 0 in reply to Isaac Porras
    TI__Prodigy 480 points
    Hi Isaac,

    You can edit the components on Webench to simulate the evaluation board. However, the max duty cycle for this device is 80%, which is why you cannot go much lower with this device. Based on your specified input voltages, I would suggest that you try something like the TLV62130A with a much higher duty cycle. The minimum is around 5.5V with your parameters.

    The minimum voltage is closed circuit under load. The load is based on your output current.
  • 0 in reply to Eric Sato31
    Prodigy 40 points
    Webench is not letting me enter a Vin below 7V for LM20343. Is it possible to just load the Eval Board configuration automatically and edit it? Also, is this minimum voltage open circuit or closed circuit under load? I'm using a battery pack for Vin, which ranges from 8.4V-5V. I did modify the Rfb1=46.4k and Rfb2=7.32k, which seemed to give me the most power output without the inductor making a buzzing noise. With this added configuration information, is 6.6V still the lowest Vin possible?
  • 0 in reply to Isaac Porras
    TI__Prodigy 480 points
    I am able to go down to 6.6V on my Webench without it mentioning that I have exceeded the duty cycle limit. The schematic tab in Webench allows you to change the values of the components and see the different bode plots and transients. However, there is nothing with a preset eval board configuration. Like I said before, the Vin is based on a closed circuit because it is assuming you are placing a load on the output. Also, due to the 80% duty cycle, 6.6V is still going to be the lowest Vin possible. I hope this helps.
  • 0 in reply to Eric Sato31
    TI__Mastermind 25590 points
    Isaac,

    I've tested the EVM in the lab and I found with 4.9VOUT, 2.33AOUT the output started to drop at VIN=6.15V

    -Sam