基于相变单元测试的高速可编程脉冲电流源

High Speed Programmable Pulsed Current Source Based on PCM Unit Test

基于相变单元电压操作的局限性,提出一种电流编程操作的方法。针对纳秒级快速相变的需求,设计了一款高速可编程的脉冲电流源,采用0.35μm标准CMOS工艺。结果显示:在10MHz编程速度的条件下,驱动脉冲电流能够良好地跟随控制信号的脉冲波形;当编程信号频率从500kHz到10 MHz变化时,输出电流变化为4.5%;当编程电阻从200Ω到10kΩ变化时,输出电流精度误差不到3%,芯片面积为0.84mm2。在高速可编程脉冲电流源的测试平台上,对相变单元进行电流编程操作,结果显示,相变电阻能够可靠地进行晶态-非晶态的高速可逆相变。

Based on the limitation of voltage operation on PCM unit, a method of current programming operation was put forward. With the need of nanosecond quick phase change, a high speed programmable pulsed current source was designed and fabricated in a 0. 35 μm standard CMOS process. It shows that driving pulsed current can well follow the pulse waveform of control signal at a programming speed of 10 MHz. The output current changes by 4.5% with the programming signal frequency ranging from 500 kHz to 10 MHz. The error of the output current is below 3% with the programming resistor ranging from 200 12 to 10 kΩ. The chip size is 0.84 mm2. On the test platform of high speed programmable pulsed current source, the PCM unit was operated with programming current, which show that phase change resistor can switch between crystalline state and amorphous state fast and reversibly.