Double ESD protection diode PESD5V0S2UAT in SOT23

Discussion in 'General Electronics Chat' started by xnihilo, Dec 1, 2008.

  1. xnihilo

    Thread Starter Active Member

    Nov 20, 2008

    In the datasheet of this component (available from digikey or philips semiconductors), at page 10, I read this:

    The pesd can protect up to two lines against damage caused by unidirectional ESD and surge pulses. It can protect lines whose polarities are below ground.

    What does that mean???
    I need to protect a line that goes to a PIC MCU pin configured as input normaly high with an internal weak pullup. Can I use this diode for line protection or not??? The MCU pin may be touched by the operator bare hand and receive an ESD that's why I have to add an extra ESD protection to the internal MCU anti ESD protection.

    Moreover I see that in application example, if the diode is used to protect two lines the connection is not the same as when protecting one line,... very weird. In the first case, pin 3 (common cathode) is connected to GND and in the second case, line to protect goes to pin 2 while pin 1 is connected to GND, the pin that normaly goes to GND is not connected. Is this logical?