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ADM3057 doesn´t have Visoout

Category: Hardware
Product Number: ADM3057EBRWZ


 Until now we were using the ADM3053 without problems. There are not stock and we are trying to change to ADM3055 or ADM3057.

We have the following schematic.We measure 5VISO in the VCC (pin3) but between pin19 (VISOOUT) and pin18 (GNDISO) don´t measure any voltage. Can you suggest me anything to have VISOOUT?




Thanks in advance,

  • Hi Rauherga,

      Looking at your schematic I'm not seeing any immediately obvious reasons which would prevent it from operating.  Quick troubleshooting things to confirm include making sure that the schematic and the board build correctly match up and make sure that there are no assembly issues such as a hidden solder bridge shorting the output. 

      Assuming that there aren't any construction/assembly related issues present, the issue must be something else.

      I notice that the filtering inductors between VISOUT and VISOIN and GNDISO and GND2 are not present.  Also the decoupling capacitors are slightly different than suggested in the datasheet.  I wouldn't have expected that either of these changes would cause the supply to misbehave and fail to operate, but its potentially possible that the omission of the filter ferrites is allowing a resulting resonance formed by the different parallel capacitors to interfere with the supply's control.

    Following the datasheet's recommendation regarding the supply decoupling, filtering and layout is strongly recommended for best performance.