设计了一种频率可调,低温漂、结构简单的张弛振荡器。该振荡器利用基准电压和负反馈的钳位作用,通过改变外部电阻的阻值来线性改变振荡周期。利用电容两端电压不能突变的原理,使得每次充放电电容电压跳变后都远离反相器的阈值,这样便忽...设计了一种频率可调,低温漂、结构简单的张弛振荡器。该振荡器利用基准电压和负反馈的钳位作用,通过改变外部电阻的阻值来线性改变振荡周期。利用电容两端电压不能突变的原理,使得每次充放电电容电压跳变后都远离反相器的阈值,这样便忽略阈值对振荡器的影响,并且省去了常规结构中的迟滞比较器,简化了电路结构,减小了振荡器的复位延时。基于0.18μm BCD(Bipolar-CMOS-DMOS)工艺模型,采用Cadence和Hspice进行仿真。在典型应用下,振荡器的频率范围为500 k Hz^2 MHz,温度在–20^+120℃变化时,振荡器的频率随温度变化的偏移量在±2.76%以内。展开更多
Carbon nanotubes （CNTs） have emerged as an important material for printed macroelectronics. However, achieving printed complementary macroelectronics solely based on CNTs is difficult because it is still challenging...Carbon nanotubes （CNTs） have emerged as an important material for printed macroelectronics. However, achieving printed complementary macroelectronics solely based on CNTs is difficult because it is still challenging to make reliable n-type CNT transistors. In this study, we report threshold voltage （Vth） tuning and printing of complementary transistors and inverters composed of thin films of CNTs and indium zinc oxide （IZO） as p-type and n-type transistors, respectively. We have optimized the Vth of p-type transistors by comparing Ti/Au and Ti/Pd as source/drain electrodes, and observed that CNT transistors with Ti/Au electrodes exhibited enhancement mode operation （Vth 〈 0）. In addition, the optimized In：Zn ratio offers good n-type transistors with high on-state current （Ion） and enhancement mode operation （Vth 〉 0）. For example, an In：Zn ratio of 2：1 yielded an enhancement mode n-type transistor with Vth - 1 V and Ion of 5.2 μA. Furthermore, by printing a CNT thin film and an IZO thin film on the same substrate, we have fabricated a complementary inverter with an output swing of 99.6% of the supply voltage and a voltage gain of 16.9. This work shows the promise of the hybrid integration of p-type CNT and n-type IZO for complementary transistors and circuits.展开更多
文摘设计了一种频率可调,低温漂、结构简单的张弛振荡器。该振荡器利用基准电压和负反馈的钳位作用,通过改变外部电阻的阻值来线性改变振荡周期。利用电容两端电压不能突变的原理,使得每次充放电电容电压跳变后都远离反相器的阈值,这样便忽略阈值对振荡器的影响,并且省去了常规结构中的迟滞比较器,简化了电路结构,减小了振荡器的复位延时。基于0.18μm BCD(Bipolar-CMOS-DMOS)工艺模型,采用Cadence和Hspice进行仿真。在典型应用下,振荡器的频率范围为500 k Hz^2 MHz,温度在–20^+120℃变化时,振荡器的频率随温度变化的偏移量在±2.76%以内。
文摘Carbon nanotubes （CNTs） have emerged as an important material for printed macroelectronics. However, achieving printed complementary macroelectronics solely based on CNTs is difficult because it is still challenging to make reliable n-type CNT transistors. In this study, we report threshold voltage （Vth） tuning and printing of complementary transistors and inverters composed of thin films of CNTs and indium zinc oxide （IZO） as p-type and n-type transistors, respectively. We have optimized the Vth of p-type transistors by comparing Ti/Au and Ti/Pd as source/drain electrodes, and observed that CNT transistors with Ti/Au electrodes exhibited enhancement mode operation （Vth 〈 0）. In addition, the optimized In：Zn ratio offers good n-type transistors with high on-state current （Ion） and enhancement mode operation （Vth 〉 0）. For example, an In：Zn ratio of 2：1 yielded an enhancement mode n-type transistor with Vth - 1 V and Ion of 5.2 μA. Furthermore, by printing a CNT thin film and an IZO thin film on the same substrate, we have fabricated a complementary inverter with an output swing of 99.6% of the supply voltage and a voltage gain of 16.9. This work shows the promise of the hybrid integration of p-type CNT and n-type IZO for complementary transistors and circuits.
