一种占空比可调的高速电平转换电路

提出一种占空比可调的高速电平转换电路,能够将频率高达1.33 GHz的低电压域信号提升至高电压域输出。在传统电平转换电路的基础上,增加了占空比调节电路,使得电路工作在不同I/O域时,通过调整接入的PMOS管数量来间接调整控制管的宽长比,进而实现占空比可调。增加了快速响应电路,引入首尾相接的反相器组,通过正反馈功能,加速实现电平转换。基于Global Foundry 14 nm CMOS工艺进行电路设计,采用SPECTRE软件进行仿真。仿真结果表明,该电路能够实现从0.9 V核心电压到2.5 V I/O电压的稳定转换,传播延时为225 ps,占空比为49.63%。当高电压域电压变换为1.8 V后,通过占空比调节电路,使占空比仍可保持在50%左右。

A High Speed Level Shifter Circuit with Adjustable Duty Cycle

A high speed level-shifting circuit with adjustable duty cycle was proposed to boost the low voltage domain signals with a frequency up to 1.33 GHz to the high voltage domain outputs. On the basis of traditional level-shifting circuits, a duty cycle regulating circuit was introduced, so that when the level-shifting circuit worked in different I/O domains, the duty cycle could be adjusted by connecting different numbers of PMOS transistors to the circuit, that was equivalent to adjust the width-length ratio of the control transistors. By adding a fast response circuit, in which the inverter group was connected end to end, the level conversion could be accelerated by the positive feedback function. The level-shifting circuit was designed in the Global Foundry 14 nm CMOS process and simulated by SPECTRE software. The simulation results showed that the circuit could achieve a stable conversion from 0.9 V core voltages to 2.5 V I/O voltages, with a propagation delay of 225 ps and a duty cycle of 49.63%. When the voltage in high voltage domain was changed to 1.8 V, the duty cycle could still be maintained at about 50% by the duty cycle regulating circuit.