ESD protection circuits using Zener diodes
US5500546A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 1994 |
| Grant date | Mar 19, 1996 |
| Priority date | — |
| Expiry date | Sep 16, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D89/611
Abstract
An electrostatic discharge protection circuit 11 coupled between an input pad 12 and operational circuitry 20 includes a primary clamp circuit 14 coupled to input pad 12, and a current limit circuit 16 coupled to primary clamp circuit 14. Primary clamp circuit 14 clamps an electrostatic discharge voltage to a first voltage value. Operational circuitry 20, susceptible to damage due to an electrostatic discharge, is coupled to current limit circuit 16 and a zener diode 30 is coupled between current limit circuit 16 and a ground potential. Zener diode 30 has a cathode terminal coupled to current limit circuit 16 and an anode terminal coupled to ground potential. Zener diode 30 further clamps a voltage across operational circuitry 20 to a second voltage which is less than 10 V, thereby protecting operational circuitry 20 from damage due to electrostatic discharge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.