Integrated circuit with improved battery protection
US4980746A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 28, 1989 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Apr 28, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D89/601
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A battery-backed integrated circuit, which receives battery power to maintain data (or logic states) when the system (external) power supply goes down. The battery power input is connected through a diode, so that the battery cannot be charged when the system power supply is active. The battery isolation diode is a junction diode, which is surrounded by a second junction. The second junction collects minority carriers which will be generated when the battery protection diode is forward biased (i.e. when the integrated circuit is being powered from the battery). Otherwise, minority carriers can diffuse to other junctions, to cause leakage currents which can significantly degrade the lifetime of a low-powered device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.