TPS79133-EP: TPS79133-EP

Part Number: TPS79133-EP

Hi,
i am using TPS79133DBVREP for one of my projects where my current requirement is 40mA.

It was working properly for initial some 10 days,but after that its giving 0V instead of 3.3V in one board and 5V(same as input voltage) in another board.
Please help me out find out the issue.

Thanks in advance

Nagendra GN

3 Replies

  • Hi Nagendra,

    TPS79101 is rated for 100mA  and assuming LDO fwd drop is about 1.5V then the load on LDO will be about 14mA.

    1. Have you checked to see if there is a short between Vin (5V) and Vout (3.3V)  internal to the IC.   If there is a short then it will result in Vin (5V) being impressed on the output.

    2. with regards to seeing zero voltage on the output have you checked to see if there is any short on the test board that you are working with,  also check to make sure output capacitor is not shorted.

  • In reply to Ramesh Khanna:

    Hi Ramesh, 

    Thanks for your inputs.

    1.  checked IC and its Output (3.3V)  and Inputs (5V)  are shorted . But i wanted to know why its shorted. is there any particular reason for that?

    2. There is no short on Board ad capacitor as well.

    I lost five ICs in two Boards but not getting why these Regulators are going bad.

    Regards

    Nagendra GN

  • In reply to Nagendra GN:

    Hi Nagendra,

    As your input voltage is 5V, is there a possibility of input voltage going higher. Recommended max input voltage is 5.5V and Absolute max rating of input is 6V as highlighted in the datasheet. Exceeding 6V on input can cause damage to the device.
    How well regulated is the input voltage?