Structure for providing electrostatic discharge protection
US5124877A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 18, 1989 |
| Grant date | Jun 23, 1992 |
| Priority date | — |
| Expiry date | Jul 18, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D89/611
Abstract
In one embodiment, the threshold voltage of the electrostatic protection circuit is selectively raised above the power supply voltage by the inclusion of a plurality of serially connected diodes connected between the power supply voltage and a discharge reference rail. The serially connected diodes become forward biased when a voltage applied to the rail is above the power supply voltage by a voltage equal to the sum of the various voltage drops across the serially connected diodes. The various input pads of the integrated circuit are connected to an anode of an associated diode, wherein the cathode of the associated diode is connected to the discharge reference rail, rather than directly to V.sub.DD as in the prior art. The anodes of each of these diodes are also connected to the device to be protected within the integrated circuit. Thus, when a voltage applied to the input pad is approximately one diode drop above the discharge reference rail, the voltage at the input pad will be shunted to the power supply voltage generator through the serially connected diodes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.