ROMJIST Volume 25, No. 2, 2022, pp. 235-245
Ionuț-Alin ILIE, Cristian Ștefan ZEGHERU, Adrian-Gabriel BĂJENARU, Gheorghe BREZEANU Battery Connected Linear Voltage Regulator for Very Low Current Consumption Automotive Applications
ABSTRACT: This paper presents a battery connected linear voltage regulator suitable for always-on automotive applications (keyless entry, car monitoring, anti-theft system). The regulator is designed as a simple 3 pins device and it is always connected to the battery, even when the car’s engine is off; therefore, a very low quiescent current of the regulator is mandatory. The regulator has a fixed 5V output voltage and can deliver up to 0.5A to the load. The total quiescent current of the proposed regulator is 3.8µA at no load and due to an adaptive biasing technique a value of 75µA is achieved at 500mA load current. The architecture include a buffer to bias the gate of pMOS pass device and so a PSRR value of 65dB at 100Hz is obtained. Moreover, being supplied directly from the automotive battery, this regulator can withstand the very harsh environment in terms of temperature, line disturbances, EMC. The proposed regulator was implemented on silicon in a 0.8µm BiCMOS technology and its characteristics were simulated and measured.KEYWORDS: pMOS; power supply rejection ratio; very low quiescent currentRead full text (pdf)