High voltage low quiescent current LDO with self-regulation impedance buffer

Lei Tian – Zhong Chen – Qinqin Li – Weiheng Wang

   To improve the whole characteristic of the LDO, a low quiescent current structure of high voltage LDO with self-regulation impedance buffer and bandgap amplifier is presented in this paper. With the bandgap amplifier proposed, the function of voltage reference and error amplifier can be achieved simultaneously, which can efficiently reduce the consumption. The load capacitor can be as small as 0.47μF by using the self-regulation impedance buffer and current buffer compensation scheme. The LDO has been implemented in a 0.18μm process with die size 0.03 mm². Without the load, the consumption quiescent current of the LDO is 1μA. Experimental result shows that the overshoot and undershoot of line transient response are less than 30 mV/V. The load regulation is about 0.1 A, and line regulation is about 0.07 mV/V at no load condition.

Keywords: LDO, self-regulation, buffer, bandgap, load capacitor

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