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TPS4H160-Q1: Device stops operating at -20'C

Sharad Yadav
Prodigy 40 points
Part Number: TPS4H160-Q1

Tool/software:

We are using TPS4H160-Q to drive Lamp load (LED),-~1A Current. 

We observed device stops working at -20'C, I am referring "Device" as tps4h160-q1 IC. 

scenarios  :100  

1) Board kept in -20'C temperature and Device output is off, when we turn on IN pin from MCU, output remains off, Fault pin remains High, CS pin remains low.

2) Board is in normal temperature, output is ON i.e. toggling, when we bring temperature down to -15 to -20'C, output intermittently turns OFF/ON, and after few blinks, it turns OFF. in this condition even after power cycle, device remains off. 

Please help us if anyone has faced such issue or there is external workaround for this issue. 

Regards, 

Sharad 

  • 0
    TI__Genius 9965 points

    Hello Sharad, 

    Can you provide a schematic of your application? 

    I would also ask if you're utilizing a GND network what diode is in place?

    In section 8.3.7.4 of the datasheet it states that "The reverse current protection diode in the GND network forward voltage should be less than 0.6 V in any circumstances."

    This could be the root of your issue but will have better luck figuring it out with more information.

    BR,

    Alan

  • 0 in reply to Alan Whitehead
    Prodigy 40 points

    Hello Alan, 

    Thanks for reply.  I will check VF at GND pin at -20'C. 

    Diode used is of ROHM make, PN - RBR3LAM40BTF. Its VF is less than 0.4V for 100mA at -25C

    Please find below snip of schematic. 

    Regards, 

    Sharad

  • +1 in reply to Sharad Yadav
    TI__Mastermind 34905 points

    Sharad,

    Looking at the schematic, one issue that sticks out here is that the CL pin is connected to the system ground, not IC ground like it is supposed to. The current limit circuitry of the high-side switch is with reference to the device's ground so the resistor should be connected before the IC resistor/diode network. What is likely happening is that at lower temperatures the resistance is increasing to a point where the current limit looks like it is being hit so the device shuts off.

    To test this out- you can short the diode/resistor network and make IC_GND the same as GND (before making any layout changes).

    Best Regards,
    Tim 

  • 0 in reply to Timothy Logan
    Prodigy 40 points

    Thanks and  for quick replies. 

    Shorted GND_1 (Pin 1) , GND_2 (Pin 12), & CL (Pin 11) and tested, solved my issue. 

    Corrected schematic & Layout as per EVK. 

    Regards, 

    Sharad

  • 0 in reply to Sharad Yadav
    TI__Mastermind 28090 points

    Hi Sharad,

    There is an existing communication we have on this specific topic with your team and the sales team, let's continue the discussion there for additional followups.

    Thanks,

    Patrick