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SN6501: If SN6501 has over-current protection when the output is short to GND.

Part Number: SN6501

Hi team,

My customer is using SN6501 to do 5V-5V isolated power as below topology. But when they do short-circuit test(short Vout to GND2), they found VCC input current increase rapidly and the SN6501device burns out. So I want to check if SN6501 has any internal over-current protection function? If it doesn't have, how should we deal with the short-circuit test? Please note customer doesn't want to add a LDO after T2 so we cannot reply on the LDO to do over-current protection. Thanks.

Best regards,

Wayne

  • Hi Wayne,

    Thank you for posting to E2E! SN6501 does not have built-in short-circuit protection like SN6505, so a current-limiting component (like LDO with built-in current limit) is needed to protect the devices from a short-circuit condition between Vout and GND2.

    A simple alternate option is to include a PTC fuse in series with the outputs, as shown below, with a hold current rating above our customer's expected output load current and trip current rating below ~320mA to protect the SN6501 primary side from sinking more than its recommended 350mA maximum at Vcc = 5V. Trip current ratings for PTCs will vary based on transformer turns ratio and SN6501 Vcc.



    Please let us know if our customer is able to consider this solution.


    Thank you,
    Manuel Chavez