| Summary: | A novel output-capacitorless low-dropout regulator (OCL-LDO) with an embedded slew-rate-enhancement (SRE) circuit is presented in this paper. The SRE circuit adopts a transient current-boost strategy to improve the slew rate at the gate of the power transistor when a large voltage spike at the output is detected. In addition, a feed-forward transconductance cell is introduced to form a push–pull output structure with the power transistor. The simulation results show that the maximum transient output voltage variation is <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>23.5</mn><mo> </mo><mi>mV</mi></mrow></semantics></math></inline-formula> when the load current <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>I</mi><mrow><mi>L</mi><mi>O</mi><mi>A</mi><mi>D</mi></mrow></msub></mrow></semantics></math></inline-formula> is stepped from <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mn>0</mn></semantics></math></inline-formula> to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>100</mn><mo> </mo><mi>mA</mi></mrow></semantics></math></inline-formula> in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>100</mn><mo> </mo><mi>ns</mi></mrow></semantics></math></inline-formula> with a load capacitance of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>100</mn><mo> </mo><mi>pF</mi></mrow></semantics></math></inline-formula>, and the settling time is <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>1.2</mn><mo> </mo><mrow><mi mathvariant="sans-serif">μ</mi><mi mathvariant="normal">s</mi></mrow></mrow></semantics></math></inline-formula>. The proposed OCL-LDO consumes a quiescent current of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>30</mn><mo> </mo><mrow><mi mathvariant="sans-serif">μ</mi><mi mathvariant="normal">A</mi></mrow></mrow></semantics></math></inline-formula> and has a dropout voltage of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>200</mn><mo> </mo><mi>mV</mi></mrow></semantics></math></inline-formula> for the maximum output current of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>100</mn><mo> </mo><mi>mA</mi></mrow></semantics></math></inline-formula>.
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