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TPS92692-Q1: TPS92692-Q1 IADJ

Takeshi Matsuzaki
Prodigy 90 points

Part Number: TPS92692-Q1

Tool/software:

Hi.

I have a question about "COMP terminal ".

When a PWM signal is input to IADJ, there is a delay in the start of boosting the LED voltage.
I would like to know if this is due to the responsiveness of current feedback.
If it is due to current feedback, would it need to change the COMP terminal constant of the phase compensation terminal?
If so, could you please tell me how to change it, even if it's just an example?

Best Regard

  • 0
    TI__Expert 7680 points

    Hi Takeshi san,

    In order for the device to fully start up, both the COMP and SS capacitor need to be charged up to their respective voltages. Which, based on your selected values, might be causing this delay. Would you be willing to post the schematic and I/O specifications and switching frequency? I would like to help resolve this ASAP. If confidentiality is a concern, you may email me at d-louis@ti.com

    Best,
    Daniel

  • 0 in reply to Daniel Louis
    Prodigy 90 points

    Hi Daniel,

    Thank you for your answer. I attached the information which you requested.
    Schematics: Block diagram for the SS and COMP pin
    I/O spec: What should we answer ?
    Switching freq: 390kHz

  • 0 in reply to Takeshi Matsuzaki
    TI__Expert 7680 points

    Hi Takeshi,

    I need a full schematic, not a block level diagram. Also, I need the input (voltage range) and output voltages, output current set point, number of LEDs and their Vf.

    I also need the following wave forms

    Inductor current
    Switch node voltage
    fault pin
    Input voltage
    Output voltage


    Please see the requested time scale and resolution depicted in Figure 1.


    Fig 1. Wave form image depicting Vin (CH1), Switch node Voltage (CH2), Vout (CH3), Inductor Current (CH4)

    Another set of wave forms showing Vin, Vss, Vcomp, and the switch node voltage.

    Again, I am more than happy to solve this over email (d-louis@ti.com) or through a meeting.

    Best,

    Daniel

  • 0 in reply to Takeshi Matsuzaki
    TI__Expert 7680 points

    Hi Takeshi San,

    Has this issue been resolved? I am happy to meet with you if you still need help.

    Best,
    Daniel