• State TI Thinks Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 344 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.

TPS2HB16-Q1: IC is not allowing the Surge Current for the load.

Nikhil Kakade
Prodigy 160 points
Part Number: TPS2HB16-Q1
Other Parts Discussed in Thread: TPS1H100-Q1

Hi Team,

We are using TPS2HB16A to Protect the Load from the OverCurrent condition. The Current limit we set was 4.1A with 25K IRlim resistor and When we connect the load it won't turn on (Max load current was 1.5A). We think it is because of the Surge current which the device is taking at the time of boot up. When we used the resistive load then it works as expected. So to Slow the Trip Timing of IC we used a 0.47uF ceramic cap in parallel with the Current Limit resistor (IRlim) and it worked. so is it recommended to use the capacitor parallel to the Current Limit resistor? or is there any other solution to increase the trip detection time for the Current limit to allow the surge current to pass.

Thanks,

Nikhil

  • 0
    TI__Genius 13310 points

    Hello Nikhil,

    Could you please tell me what the capacitance on your load is?

    Regards,

    Kalin Burnside

  • 0 in reply to Kalin Burnside
    Prodigy 160 points

    Hi Kalin,

    The Capacitance of the load is around 1000uF for each channel.

    We have also tested the Short Circuit and Over Current Protection test and they are working perfectly. 

    Thanks,

    Nikhil

  • 0 in reply to Nikhil Kakade
    TI__Genius 13310 points

    Hello Nikhil,

    We do not recommend placing capacitance on the ILim line. Any capacitance on the ILim line is detrimental to the current limit performance. With the slew rate of the TPS2HB16A and such a large capacitance on your load the inrush current will cause your device to hit the current limit threshold and go into thermal shutdown. What are the operating conditions and what is the reason for 1000uF on the output? What features on TPS2HB16-Q1 are must-haves for you?

    Regards,

    Kalin Burnside

  • 0 in reply to Kalin Burnside
    Prodigy 160 points

    Hi Kalin,

    We are powering third-party 4K LED Display from our circuit which is working on 15V and Max Current will be 1.8A. To Protect the Display as well as other circuit components from the short circuit and overcurrent, we are using the TPS2HB16A IC. we don't require Precise current limiting (Currently we have set the IC at 4A limit). Can you please elaborate what exactly it means when you say detrimental current limit performance (does it increases the time to cut the power after any fault condition).

    Thanks,

    Nikhil

  • 0 in reply to Nikhil Kakade
    TI__Genius 13310 points

    Hello Nikhil,

    The HB16 device will not work for your use-case. The in-rush current will cause the device to shut off immediately and will not allow for the capacitance on your load to be charged. The capacitor you placed in parallel with your Rlim essentially changed the current limit trip point which allowed for the inrush current to pass. You will need a device that will clamp the current to an acceptable level and charge the capacitance over a longer period of time without causing a thermal shutdown. We do not have a 2 channel device that can handle your requirements, but the TPS1H100-Q1 I believe would work if you use it for each output. I will look into this more and get back to you by EOD Thursday.

    For more information regarding driving capacitive loads please read: How To Drive Resistive, Inductive, Capacitive, and Lighting Loads (Rev. B)

    Regards,

    Kalin Burnside

  • 0 in reply to Kalin Burnside
    TI__Genius 13310 points

    Hello Nikhil,

    The TPS1H100-Q1 can handle your requirements. It would be able to safely charge the 1uF of capacitance without going into thermal shutdown, and provide short-ground protection (among other fault protections). You could also look into the TPS1H200-Q1, the better value option, and see if it fits better for you; However, its nominal operating current is below the TPS1H100-Q1 and also doesn't offer current sense. 

    Regards,

    Kalin Burnside