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.

TLE4275-Q1: TLE4275-Q1 as load

Part Number: TLE4275-Q1

VCC=5V  BATTERY=0V

We have used TLE4275-Q1 as load when down the F/W. we found the VCC (from USB) is instability ,so that the down failure. Could you help check What caused the issue ,Leakage currentor capacitive load,and so on

PS: we replace Infineon‘TLE4275 and ON'TLE4275,the down can work normally

  • Hi Hope,

    The schematic you attached is unreadable. Will you please resend it?

    Regards,
    Jason Song
  • Hi Hope,

    In order to better assist you on the issue of the instabilities, I will need scope shot including Vin, Vout and Load current. Especially the scopeshot that shows the characteristics of the instabilities.

    The schematic you posted is pixelated and I cannot read the values for the capacitors used in the schematic. If possible, will you also include the layout of the board? Instead of taking a picture of the circuit using phones, you could use a tool in windows called "snipping tool" to take a screenshot directly from your computer and it will help us to better understand your schematic.

    Regards,
    Jason Song
  • Dear Jason,
            The TLE4275 need no work when the down F/W due to the VIN is open. so that TLE4275 working like load and the output is connected to 5v form JTAG.The total output capacitance of TLE4275 is about 150uf.

           The same application,The down F/W is ok when use the competitor device,but TI'TLE4275 cann't work normally. could you help explain the difference between TLE4275 and  Infineon‘TLE4275 and ON'TLE4275

           Ps:  The down can success when use TI‘TLE4275. but it is instability and need longer timer for the down

    Thanks a lot

        

     

          

  • Dear Jason,

         I summary the question is as below, please give a hand for us

    1, SCH is as below

    2, Describe

    A,TLE4275’VIN=0

    B,VCC5C=5V(from JTAG)

    C,TLE4275’RESET is used to reset the MCU when down F/W

       After testing, when down F/W with JTAG ,we found the TLE4275’RESET is low, which the MCU can’t reset and down F/W failure. But we replace the Infineon:TLE4275G with P2P,the TLE4275G’ RQ(Rest) is high ,and the F/W can down success. It is strange that TI TLE4275’ RESET is partly high and partly low in the same design. Would you help check the What the reason is and give some advices for the issue

    PS:Could you share your mail to me for more effective communication

  • Hi Hope,

    As this issue will be discussed via private message, I am closing the post.

    Regards,
    Jason Song
  • Just for other people who has similar questions, the proposed solutions are as the following:

    When 5V is used for MCU FW uploading, the added 5V at Vout pin of the TLE4275-Q1 will charge its input node to around 1.5V with Vin floating. At Vin=1.5V, the logic circuitry has not been fully powered on. That’s the reason causing RESET pin to be undefined. In order to fix this, there are two possible solutions:

    1. If MCU FW downloading voltage can be adjusted, increasing the voltage applied at the Vout will charge Vin pin to a higher voltage. Hope Chen has mentioned that with 12V charging voltage on the Vout, the issue has disappeared.
    2. If allowed, an diode can be added to the existed circuitry that will be turned on with 5V on the Vout pin. Once the diode has been turned on, Vin will be charged to Vout voltage minus a diode voltage drop. Depending on the diode being picked, the Vin voltage could be around 4.3 – 4.7 V. This will also help to fully powered on the internal logic circuitry that will make RESET pin high during FW uploading.

    Regards,
    Jason Song