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TINA/Spice/LM3488: TINA/Spice/LM3488

Prodigy 150 points

Replies: 22

Views: 360

Part Number: LM3488

Tool/software: TINA-TI or Spice Models

I am trying simulate the LM3488 in a boost configuration with VIN supplied from another source. The input voltage is 1.3 VDC with the output voltage set to 4VDC. The simulation works fine if I don't load the output. As soon as a load is applied the output drops to near 0 volts and the MOSFET gate drive stays high. There is also a large (and not unexpected) increase in the MOSFET current. It's at this point that the LM3488 stops driving the MOSFET. Schematic and simulation results attached.2480.SCHEMATIC1 _ PAGE1.pdf

  • In reply to Dean Munson:

    Hi Dean,

    Thank you for considering the LM3488. Please increase your current sense resistor to 0.06. The circuit seems having inadequate current limit threshold, thus triggering the max duty cycle.

    You may also consider the LM5155, our latest boost controller.

    Thanks,
    Youhao
  • In reply to Youhao Xi:

    7776.boost.pdfMore or less same result except the MOSFET gate drive goes to 0 volts.

  • In reply to Dean Munson:

    Tried increasing output cap to 1000uF but the LM3488 stops switching 2mS into the simulation.

  • In reply to Dean Munson:

    Did you increase the current sense resistor as we suggested?
  • In reply to Youhao Xi:

    Sorry for the slow response. Was out of town. 

    I did increase the sense resistor as suggested but as I stated in my last post the result was the same except that the peak current was reduced and after the device stopped switching the gate drive pin went to 0 volts.

  • In reply to Dean Munson:

    Please attach your TINA native file so we can take a look.
  • In reply to Youhao Xi:

    What is the TINA native file ? I am using the .lib file included with the .zip file. The .lib file is referenced via the Pspice profile editor under Configuration files/library.
  • In reply to Dean Munson:

    Hi Dean,

    It is your original TINA model file, which should be the zip file.

    Thanks,
    Youhao
  • In reply to Youhao Xi:

    snvmax0b.zip

    Zip File attached