This paper presented a capacitor-less low-dropout(LDO)linear regulator circuit,which utilized active frequency compensation(AFC)circuit together with adaptive biasing circuit to achieve fast transient response over a wide load range.The active frequency compensation(AFC)circuit adopted a dual-loop differentiator structure,which not only effectively reduced the area of the on-chip compensation capacitor,but also improved the transient response of the overall circuit.The adaptive biasing circuit with the source follower structure was used as the bias for the active frequency compensation circuit.It further improved the transient response of the linear regulator circuit.The capacitor-less LDO was fabricated using the SMIC 0.18 μm standard CMOS process with an effective die area of 0.038 mm2.The simulation results show that a maximum output current of 150 mA is achieved at a dropout voltage of 200 mV,and the maximum load capacitance is 100 pF.With a maximum load current change over an edge time of 100 ns,the overshoot and undershoot voltages are 185 mV and 405 mV,respectively,and the circuit settling time are 0.45 μs and 0.2 μs,respectively.
关键词
无片外电容/有源频率补偿/源随器/自适应偏置/快速瞬态响应
Key words
capacitor-less/active frequency compensation/source follower/adaptive bias/fast transient response
维普
万方数据