一种采用仿峰值电流模式的Buck型DC-DC设计

A Design of Buck DC-DC Based on Simulated Peak Current Mode

电压模式和峰值电流模式是PWM降压DC-DC最常采用的反馈控制方式,二者优缺点明显。提出了一种名为仿峰值电流模式的新型PWM控制模式,该模式通过逐周期模拟电感电流动态变化的方式,对Buck型DC-DC电路进行调节控制,使电路既保留了峰值电流模式动态响应速度快、逐脉冲过流检测、补偿结构简单等特点,又具有了电压模式抗噪声能力强且占空比调节不受限制的特点。基于UMC 0.25μm 2P5M BCD工艺,设计一款采用仿峰值电流模式的宽输入电压的Buck型DC-DC。使用Hspice对Buck DC-DC进行整体性能和功能仿真,证明了该仿峰值电流模式结构的优越性,并完成电路版图设计和流片。

Voltage mode and peak current mode is the most commonly used feedback control method of PWM Buck DC-DC, both of which have obvious advantages and disadvantages. In this paper, a new PWM control mode named simulated peak current mode is proposed, which adjusts and controls the Buck DC-DC by periodically simulating the change of the inductor current cycle by cycle. Make the circuit not only retains the peak current mode dynamic response speed, pulse by pulse over current detection, compensation structure is simple, but also has the voltage mode anti-noise ability, duty cycle adjustment is not limited. Based on the UMC 0.25 μm 2P5M BCD process, a Buck type DC-DC with a wide input voltage with an analog peak current mode is designed. Then, the functional simulation of Buck DC-DC is carried out by Hspice, which proves the superiority of the simulated peak current mode. Finally, the circuit layout design is completed.