ROMJIST Volume 29, No. 2, 2026, pp. 143-154, DOI: 10.59277/ROMJIST.2026.2.04
Paul COSTE, Paul MIRESAN, Marius NEAG, Cristian RADUCAN, Marina TOPA, Istvan KOVACS Automotive Capacitor-Less Linear Regulator with Active Capacitance Multiplier Frequency Compensation and AI-Assisted Sizing
ABSTRACT: This paper presents a solution for implementing frequency-compensation of low-power automotive output-capacitor-less linear regulators able to operate over a wide supply voltage range. First, a novel Active-Capacitive-Multiplier (ACM) is introduced that emulates the passive, R-series-C, frequency compensation network of a conventional NMOS regulator. Two design examples are shown that follow the same approach: the conventional NMOS regulator with RC compensation is sized to meet a set of real-life requirements; next, the RC network is replaced by the proposed ACM, sized so the resulting regulator has loop gain frequency characteristics similar to the conventional one; then the performances of regulators with conventional-RC and ACM-based frequency-compensation are compared. The ACM-based regulator exhibits significantly better response to fast transients: the output voltage undershoot/overshoot is reduced by about 3x for the NMOS regulator. The ACM has a negative impact on the power supply rejection (PSR) of the NMOS regulator. Third, an effective way of scaling up the load current of such regulators is presented: starting from the NMOS ACM-based regulator described above, with a maximum load current of 100 mA, an AI-assisted optimized sizing procedure was developed to re-size the pass-device and key ACM elements, so that the resulting regulator can handle loads up to 200 mA.KEYWORDS: Active capacitance multiplier; AI-assisted sizing; artificial intelligence; automotive; capacitor-less regulators; linear voltage regulator; microelectronicsRead full text (pdf)