一种用于RF供电的混合结构DC-DC变换器

A Hybrid DC-DC Converter for RF Power Supply Application

设计了一种基于0.13μm CMOS工艺的混合结构DC-DC变换器。该变换器由Buck变换器和LDO串联组成。Buck变换器输出电压可根据LDO负载电流进行调节,能有效减小LDO损耗。在负载电流为20mA时,可将整个变换器的效率提高10.5%。LDO采用片外电容补偿。高带宽误差放大器使LDO在DC^20 MHz范围内具有较高的电源抑制比。LDO对Buck变换器开关频率处的噪声抑制达-62dB。整个电源具有较低的输出噪声,适于为RF电路供电。

A hybrid DC-DC converter for RF power supply application based on 0. 13 μm CMOS IC process was presented. The converter was implemented by successively cascading a Buck and a low dropout regulator（LDO）. The output of the Buck could be adjusted according to the load current of the LDO, which significantly reduced the efficiency loss due to LDO. The efficiency of the hybrid converter at 20 mA load current had been increased by 10.5%. An external capacitor was used for LDO loop compensation. A high bandwidth error amplifier was designed to improve the power supply rejection ratio（PSRR） of the LDO at frequencies from DC to 20 MHz. The LDO was capable to suppress noise at the switching frequency of Buck by -62 dB. The output noise of the hybrid converter was very low, which made this converter very suitable for RF power supply application.