基于动态随机均衡的电流舵数模转换器设计

A current-steering digital-to-analog converter design based on dynamic random equilibrium

在宽带通信、高速视频传输等领域中,由于受到时钟抖动、随机噪声等非理想因素的影响,电流舵数模转换器的动态性能受到极大限制。针对该问题,提出一种动态随机均衡的电流源选择算法。其核心思想是基于“数据比对的方向性及方位随机均衡选择”,在维持低开关活动性的同时,将误差进行随机均衡,转换为白噪声,提高数模转换器的输出动态范围。14 bit/400 MHz数模转换器采用SMIC 0.18μm CMOS工艺进行流片验证。测试结果表明,在电源电压1.8 V、时钟频率400 MHz时,无杂散动态范围达到90.1 dB,平均功耗为86 mW。

In the field of wideband communications and high-speed video transmission,due to the influence of non-ideal factors such as jitter and random noise,the dynamic performance of current-steering digital-to-analog converter(DAC)is greatly limited.To solve this problem,this paper proposes a new method of dynamic random equilibrium for current source selection,whose core idea is based on"data comparison direction and position random equilibrium".It converts error to white noise when maintaining the low switching activity at the same time,so as to improve the output dynamic range.The 14 bit/400 MHz DAC is implemented with SMIC 0.18μm CMOS technology and the test results show that with 1.8 V power supply and 400 MHz clock frequency,the spurious-free dynamic range(SFDR)is 90.1 dB and power consumption is 86 mW.