一种采用新颖的双重自适应补偿的低静态电流LDO稳压器的设计

Design of a Low Quiescent Current Low-Dropout Regulator with Novel Dual Active Compensation

设计了一种采用双重自适应补偿的两级结构LDO线性稳压器,该补偿技术能够产生两个随负载变化的零点以抵消不同负载条件下的极点变化带来的影响,从而保证系统的稳定性.与传统的设计方法相比,该补偿方法几乎不消耗电流,文中设计的LDO静态电流小于1μA,并且采用折返式电流限制,减小了芯片的功耗.采用该双重自适应补偿的LDO已在Hy-nix0.5μmCMOS工艺线投片,当负载电流为300mA时,漏失电压为150mV,线性调整率为2mV/V,负载调整率为0.75%.测试结果表明,采用该双重自适应补偿结构的LDO工作良好.

In order to improve the accuracy of the output voltage of a LDO,which consumes low quiescent current,a novel dual active compensation technique is used to design a LDO. It can produce two system zeros varying from load current to cancel the negative effect of the pole at different loads on the system＇s stability. Compared with traditional compensation,the dual active compensation does not consume current. The quiescent current of the proposed LDO is less than IμA, and the fold back current limit reduces the power consumption of the chip. A low quiescent current LDO employing the dual active compensation technique is implemented in a Hynix 0.5μm CMOS process. The dropout voltage is 150mV when the load current is 300mA,the line regulation is 2mV/V, and the load regulation is 0.75% ,indicating that the circuit works well and effectively.