多相BUCK相数自动调整模块的设计与实现

An Auto Phase Control Module Design in Multiphase BUCK Converter

针对智能手持设备多核处理器供电模块中的散热设计和效率难题,提出了一种多相交错BUCK以及相位个数自动调整装置。在此基础上完成了一款三相BUCK的电路实现,该电路能够根据负载运行的区间范围增加或减少支路个数,从而实现在整个负载范围内保持较高的转换效率。此外,为克服相位个数判断延迟造成的输出电压跌落,完整的实现电路还包含了一个抑制输出电压快速跌落的功能模块。芯片基于0.18μm CMOS pure 5V工艺设计并完成投片测试,测试结果满足最大输出电流6A,相位个数自动调整装置运转正常,0.9V输出电压下,在4A范围内满足不低于80%的转换效率。

In view of the heat dissipation design and efficiency problem in the power supply module of the smart mobile device,a multiphase interleaved BUCK and automatic phase adjustment mechanism were proposed.On the basis of this,a three-phase BUCK circuit was realized.The circuit could increase or decrease the number of branches according to the operation load,so as to achieve a high conversion efficiency in the whole load range.In addition,in order to overcome the output voltage drop caused by the phase adjust delay,a function module to suppress fast voltage drop was also included in the complete circuit.The chip was designed based on a 0.18μm CMOS pure 5Vprocess and the lab tests had been completed.It is showed that the chip meets the maximum output current of 6Aand the automatic phase adjustment mechanism works well,and at 0.9Voutput voltage not less than 80% conversion efficiency is achieved within the scope of 4Aload current.