Macronix International Co., Ltd.

Baw-Chyuan Lin

Ming-Shang Chen

Wenpin Lu

Mam-Tsung Wang

Chun-Lien Su

Ying-Che Lo

Current source component with process tracking characteristics for compact programmed Vt distribution of flash EPROM

Method for soft-programming at least one floating gate memory cell in at least one page of a persistent memory device by converging the low threshold voltages of the several cells of the page within an optimal range, and apparatus implementing the method. The methodology of the present invention teaches connecting the individual drains of the several memory cells of the device of a given page, or block, to a voltage limited constant current circuitry component. The methodology applies a first positive voltage to the word line of the page and a second positive voltage to the common source in a fixed time period to converge the pages low threshold voltage distribution. The methodology is capable of implementation on either the source or drain side of the memory array.

Auto-stopped page soft-programming method with voltage limited component

An apparatus for programming selected floating gate storage transistors in a data storage device includes a voltage supply circuit, coupled to the control gate and the source of a selected floating gate storage transistor, to supply a gate programming potential across the control gate and the source to move charge in the floating gate. Circuitry, coupled to the selected floating gate storage transistor, maintains drain current of the selected floating gate transistor at a substantially stable value during programming. In one example, the circuitry is a stable current source in parallel with a load coupled to the source of the selected floating gate transistor. The stable current source, in one embodiment, is a current mirror designed to supply a fixed current level. The load may be a resistor chosen to control a slope of a curve of source current versus source voltage such that drain current variation is limited. The load may be a diode chosen to control a slope of a curve of source current versus source voltage such that drain current variation is limited.

Apparatus and method for programming of flash EPROM memory

Growing community of inventors

Yunlin, Taiwan

Baw-Chyuan Lin