• State
  • Locked Locked
  • Replies 5 replies
  • Subscribers 62 subscribers
  • Views 130 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.

Original question:

TLV61220： TLV61220 output problem(Iout 20ma+)

TLV61220: Output volatge is dropping after connecting to load

Shubin Kanchan
Prodigy 80 points
Part Number: TLV61220
Other Parts Discussed in Thread: BQ25601

I've designed the boost converter to 5V, 90mA output current for 3.6V input.

Without connecting to the load I'm getting 5V output.

After connecting to the load the volatge is dropping to 4V.

Please let me know the reason for this.

Thanks and regards,

Shubin

  • 0
    TI__Mastermind 21565 points

    Hi Shubin:

    May you measure the Vin/Vout/SW/FB waveform? Better with inductance current.

    And what's the load exactly during the test? 

  • 0 in reply to Minqiu Xie
    Prodigy 80 points

    Dear Minqiu,

    I'm working from home and I don't have any equipments to measure anything now. Below is my observations during the testing.

    I've rigged up the circuit in General purpose PCB.

    I have have connected it to the USB_OTG_VBUS pin of the I.MX6ULL processor. The maximum current of this pin is 50mA. I also measured the current it was showing around 1mA.

    Also for the testing I connected a 100 ohm load resistor. current through the load was 30mA and voltage across it was 3V.

    Thanks and regards,

    Shubin

  • 0 in reply to Shubin Kanchan
    TI__Mastermind 21565 points

    Hi Shubin:

    The USB_OTP is just for test or final application? The maximum current is only 50mA, I afraid it doesn't have enough capability to supply the circuit.

    As there is no waveform yet, I suspect the issue is caused by the weak power supply. The input voltage may drops a lot during startup and loading. 

  • 0 in reply to Minqiu Xie
    Prodigy 80 points

    Hi Minqiu,

    The USB_OTG is our final application.

    The Boost regulator is powered by Battery charger IC BQ25601. The output voltage of this is 3.6V.

    I didn't understood this point: "The maximum current is only 50mA, I afraid it doesn't have enough capability to supply the circuit."

    Could you please elaborate it.

    Thanks and regards,

    Shubin

  • 0 in reply to Shubin Kanchan
    TI__Mastermind 21565 points

    Hi Shubin:

    So sorry, I'm still confused about your system. I thought it was supplied by the OTG with 50mA current limit before. I wonder if you could draw a simple system blocks for me? To better understand the input, load, and control principle.

    Actually, the waveform is the most direct way to locate the issue.