高可靠性的闪存字线驱动电路设计

摘要

This paper presents a high reliable flash memory word line driver circuit which provides negative and positive high voltage for flash to program or erase. This circuit adopts the isolation technology to make the voltage stable and isolates the drop-down pathway which has a competition with the output node. It effectively overcomes the common issues of voltage competition in the level shift circuits. This approach not only guarantees the correct voltage for program/erase cycles but also ensures that the circuit works steadily and reliably. The proposed word line driver is able to drive high output loads through appropriately designing the size of transistors. This advantage may eliminate great effects of word line parasitic capacitance resulting from larger memory capacity. Simulation results show that even if driving 3pf large capacitance, this circuit can still work normally.%本文提出了一种高可靠性的闪存字线驱动电路，为闪存编程或擦除操作提供负高压或正高压。该电路采用隔离稳压技术，隔断了与输出端存在竞争的下拉通路，有效克服了电平转换电路中普遍存在的电压竞争问题，使得输出端准确输出所需编程/擦除电压，保证电路工作稳定可靠。通过合理设计MOS管尺寸，该电路还具有较强的负载驱动能力，可以有效消除由于存储容量大而带来的巨大字线寄生电容的影响，仿真结果显示，即使驱动3pf的大电容，电路仍可以保证正常功能。