High voltage negative charge pump with low voltage CMOS transistors
AssigneeTexas Instruments Incorporated
InventorsTim M. Coffman, Sung-Wei Lin
Life of this patent
Estimating the term…
Abstract
An improved negative charge pump system for erasing a memory array in a memory which has a supply voltage and a negative charge pump. The negative charge pump system includes (a) a device for selecting a memory array to be erased; (b) a device for switching on the supply voltage Vnn for the charge pump; (c) a device for pumping the supply voltage Vnn with the charge pump to produce a pumped negative voltage; (d) a device for erasing the selected array with the pumped negative voltage; (e) a device for stopping the pumping; and (f) a device for providing a discharge path for voltages trapped in the charge pump.
Claims2
A method for erasing a memory array in a memory which has a supply voltage and a negative charge having multiple stages, comprising the steps of:
- (a) selecting a memory array to be erased;
- (b) applying the supply voltage to the charge pump;
- (c) pumping the supply voltage to produce a pumped negative voltage from a negative at each of said multiple stages of said negative charge pump;
- (d) erasing the selected array with the pumped negative voltage;
- (e) stopping said erasing;
- and
- (f) providing a separate discharge path for the negative voltage trapped in each stage of the charge pump.
An improved negative charge pump system for erasing a memory array in a memory which has a supply voltage and a negative charge pump having multiple stages, comprising:
- (a) means for selecting a memory array to be erased;
- (b) means for applying the supply voltage to the charge pump;
- (c) means for pumping the supply voltage to produce a pumped negative voltage from a negative voltage at each of said multiple stages of said negative charge pump;
- (d) means for erasing the selecting array with the pumped negative voltage;
- (e) means for stopping said erasing;
- and
- (f) means for providing a separate discharge path for each of said negative voltages trapped in each said stage of the charge pump.
Dependencies are inferred from the claim text.