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Diode SMB package problem

autodeskguest

Hi all,

 

I made a simple board using eagle v5.6, and I've noticed that on the board

file, all smd diode with package SMB have the polarity band is on the

positive pin, but in the datasheet the positive band indicates the cathode.

 

Is this an EAGLE bug or am I missing something?

 

Kind Regards

Lorenzo

 

 

 

 

Parents

  • Lorenzo,

     

    I am looking at SMB.pac from "smd-ipc.lbr". In this case there is no

    "band" but the diode symbol is shown. Also, the pins are named "1" for

    Cathode and "2" for Anode.

     

    When you say the "polarity band" is on the "positive pin", what do you

    really mean? For a Zener, positive is connected to the cathode because it

    operates in reverse breakdown mode. If a normal diode is placed across a

    relay coil for inductive kick-back protection, positive is also connected

    to the cathode because the kick-back is of the opposite polarity of the

    driving voltage. But, if you want a diode to conduct in the forward

    direction, then the positive is connected to the anode.

     

    I have not seen any standard library parts built incorrectly.

     

    Regards,

    --

    Jeff Rockel

    WI, USA

    --

    Browser access to CadSoft Support Forums at http://www.eaglecentral.ca

     

Reply

  • Lorenzo,

     

    I am looking at SMB.pac from "smd-ipc.lbr". In this case there is no

    "band" but the diode symbol is shown. Also, the pins are named "1" for

    Cathode and "2" for Anode.

     

    When you say the "polarity band" is on the "positive pin", what do you

    really mean? For a Zener, positive is connected to the cathode because it

    operates in reverse breakdown mode. If a normal diode is placed across a

    relay coil for inductive kick-back protection, positive is also connected

    to the cathode because the kick-back is of the opposite polarity of the

    driving voltage. But, if you want a diode to conduct in the forward

    direction, then the positive is connected to the anode.

     

    I have not seen any standard library parts built incorrectly.

     

    Regards,

    --

    Jeff Rockel

    WI, USA

    --

    Browser access to CadSoft Support Forums at http://www.eaglecentral.ca

     

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