Integrated circuit timer function using natural decay of charge stored in a dielectric
US5760644A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 1996 |
| Grant date | Jun 2, 1998 |
| Priority date | — |
| Expiry date | Oct 25, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/0757
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A semiconductor integrated circuit to determine a passage of time that may include a time during which no electrical power is supplied to the circuit is disclosed. The circuit has a timing device that includes a memory storage dielectric material for trapping charge carriers and releasing the trapped charge carriers in a known manner over time. The timing device has an electrical parameter that is relatable to an electric field created by the trapped charge carriers. A charge injection circuit is provided for selectively injecting charge carriers into the memory storage dielectric material to create an initialized state, and a time reader circuit determines when the electrical parameter has reached a predetermined value that corresponds to a passage of a predetermined time. Preferably the timing device is an insulated gate field effect transistor in which the memory storage dielectric material is a dielectric material, such as SONOS or SNOS, between the gate and channel overlying at least the channel area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.