An SPICE model for phase-change memory simulations

Along with a series of research works on the physical prototype and properties of the memory cell,an SPICE model for phase-change memory(PCM) simulations based on Verilog-A language is presented.By handling it with the heat distribution algorithm,threshold switching theory and the crystallization kinetic model,the proposed SPICE model can effectively reproduce the physical behaviors of the phase-change memory cell.In particular,it can emulate the cell’s temperature curve and crystallinity profile during the programming process,which can enable us to clearly understand the PCM’s working principle and program process.     

高电源抑制比低温漂带隙基准源设计

根据带隙基准的基本原理,结合含三条支路负反馈的电流源,设计了一种高阶补偿的带隙基准源电路。实现了对温度的2阶补偿和3阶补偿,获得了一种高电源抑制比、低温漂、不受电源变化影响的电压基准源。设计采用0.35μm CMOS工艺,仿真结果表明,在-40℃～125℃温度范围内,输出电压的温度系数为7.70×10-7/℃,在1kHz时,电源抑制比为-82.3dB。