针对Buck型开关稳压器的断续工作模式(DCM),基于CSMC 0.5μmCMOS工艺设计实现了一种新颖的负载电流检测电路。同传统的电感电流采样方式不同,该结构直接应用与负载电流变化几乎同步的同步管栅极驱动信号作为“电流采样”信号,实现了负载平均电流的检测。经投片验证,提出的电流检测电路工作良好,且面积仅占芯片的1.5%,同传统采样方式相比,面积减小了21%.静态时的耗电仅为原来的40%。
By adopting CSMC 0. 5μm CMOS process, a novel load current sensing circuit is presented for DCM of BUCK switching regulator. Different from the traditional inductor current sensing circuit, the sensing of load current is realized by detecting the gate driver signal of synchronous MOSFET which changes with the load current simultaneously. The measurement result shows that the proposed current sensing circuit works normally in the fabricated chip for verification. The circuit occupies only 1.5% area of the chip. Comparing with traditional method, the area is reduced by 21% and power dissipation is only 40% of that.