Back to the Future: An All-NMOS SiC Linear Voltage Regulator for High Temperature Applications

The first power management option in integrated SiC is presented in this paper. This linear voltage regulator consists of an error amplifier and a W/L=32,000 depletion NMOS as the pass device. The feedback and frequency compensation networks are external. Due to the developing nature of SiC processes, the voltage reference used for the error amplifier is external as well. This SiC linear voltage regulator was fabricated in a 4H-SiC, all NMOS, 2 μm process and can operate at temperatures up to 225°C. The voltage regulator can regulate at voltages between 10 and 15 V up to a maximum load current of 2 A with less than 4% load regulation and 192 mV/V line regulation at 225°C. This regulator sets the reference for future SiC linear regulators, and as the manufacturing processes for SiC mature, better load and line regulations will be achievable and yet over a wider temperature range and higher output voltages than standard silicon.