• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 63 subscribers
  • Views 590 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.

TPS92602-Q1: low/high beam switch issue

Jack Deng
Expert 1090 points
Part Number: TPS92602-Q1
Other Parts Discussed in Thread: TPS92602EVM

Hi TI guys:

I am using the TPS92602-Q1 in my project, but there is a problem need your help.

when I turn on the VBAT1, the low beam work normally, then I change the power supply form VBAT1 to VBAT2, the high beam can't  work normally.

Low/High beam can't switch directly, I need to OFF/ON the power supply.

The TPS92602EVM has the same problem, do you have any advice to solve this problem?

I look forward to hearing form you soon, thx

  • 0
    TI__Expert 5475 points

    Hi Jack,

    I'm not very clear about the issue that you described. Would you please share more details? Do low beam and high beam share the same circuits and LEDs? Or with different channel? And what is the test you do on the EVM? We have not seen this issue before. Thanks.

    Best Regards,

    Shirley He

  • 0 in reply to Shirley He
    Expert 1090 points

    Hi Shirley：
    I'm sorry.

    Just check with RD, the issue as below:

    there are two separate channels, each Iout=700mA, three LEDs series.(each 9V/700mA)

    I only turn on the power supply (VBAT1=12V) to low beam, the low beam can shine, then I turn on the power supply(VBAT2=12V) to high beam, the high beam can't shine.

    I turn on the VBAT1 and VBAT2 at the same time, High/Low beam can all work properly.

    Repeating the same test on EVM, the problem also has existed.

  • 0 in reply to Jack Deng
    TI__Expert 5475 points

    Hi Jack,

    May I ask how the PWM voltage is connected in your design?

    I checked the phenomenon on the EVM. On our EVM, if both PWM are connected to VDD that comes from an external LDO, then PWM will be high before second channel is turned on. In that case, the second channel will be regarded as short. For this device, if short or overcurrent is detected, in order to reset the controller, there must be one disable-and-enable cycle for the affected channel. So when using this device, PWM voltage should be provided after supply is turned on.

    Best regards,