Protecting Chip Cards Against Electrostatic Discharge
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-03
It is proposed that a chip card be protected against electrostatic discharge (ESD) by short-circuiting the chip contacts at times at which the card is neither read nor written. A chip card is a data carrier in the general shape of a credit card and comprises one or more integrated circuit (IC) chips for logic and/or memory functions. Similar to credit cards, chip cards will become objects of daily use and thus must be readily usable. For this purpose, the logic chip of the card must be protected against destruction or undesired changes of the written information by electrostatic discharge. The I/O pads of the FET chips are protected by what are known as ESD diodes which are generally special devices with a low breakdown voltage to the substrate.