High voltage precharging circuit
US4703196A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 8, 1985 |
| Grant date | Oct 27, 1987 |
| Priority date | — |
| Expiry date | Aug 8, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A precharging circuit employing ordinary enhancement (E) types MIST'S produces erasing and writing (E-W) voltages to change the data stored in an EEPROM fabricated in a common memory chip with the circuit. The E-W voltage increases gradually from a low level to a high level over a long time interval determined substantially by a long time constant RC circuit, the voltage charge developed on the capacitor C comprising the E-W voltage. The resistor R is implemented by a first MIST connected between a high voltage source and the capacitor C, the gate thereof being controlled by a charge-pump (CP) circuit and a second MIST. The CP circuit is connected between the capacitor C and the gate of the first MIST and is rendered operative during successive clock pulses of a series of clock pulses applied thereto. The CP circuit, during each clock interval, produces a voltage output applied to the first MIST which exceeds the threshold voltage V.sub.th thereof, whereby the first MIST periodically is turned ON for conducting a charging current which flows into the capacitor C. The second MIST is connected between the gate of the first MIST and the capacitor C for suppressing the gate voltage of …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.