具有快速瞬态响应的电压模式Buck变换器

A Voltage Mode Buck Converter with Fast Transient Response

针对电压模式的Buck变换器,提出了一种新颖的参考电压可选择设计方案。在负载电流改变的情况下,通过参考电压选择电路和阈值电压控制电路来选择不同的参考电压,加快占空比的改变。采用SMIC 0.18μm CMOS工艺进行设计与仿真,结果表明,该变换器在负载发生590mA瞬态变化时的输出过冲电压小于50mV,并且瞬态恢复时间小于12μs。与传统的电压控制模式相比,该变换器具有更好的瞬态响应性能。

A novel reference voltage selectable scheme in voltage mode buck converters was presented.The proposed scheme was based on a reference voltage select circuit and a threshold voltage control circuit.It could select different reference voltage when the load current changed,so the change of duty cycles could be accelerated.The voltage mode buck converter had been designed and fabricated in SMIC 0.18μm CMOS process.Simulation results showed that it achieved an output overshoot voltage less than 50 mV and a recovery time of 12μs under 590 mA step load change.Compared with conventional PWM voltage mode buck converters,the proposed converter had better performances of transient response.