A high-temperature, high-voltage, fast response linear voltage regulator

This paper reports a high-temperature integrated linear voltage regulator implemented in a 0.8-μm BCD (bipolar, CMOS and DMOS)-on-silicon-on-insulator process. This step-down voltage regulator converts an unregulated high input DC voltage to a regulated nominal CMOS voltage (i.e. 5 V) for the low-side buffer (pre-driver) and other digital and analog building blocks of a high-temperature integrated gate driver circuit. An error amplifier inside the regulator has been designed using inversion coefficient methodology, and a temperature stable current reference has been used to bias the error amplifier. The linear regulator provides an output voltage of 5.3 V at room temperature and can supply a maximum load current of 200 mA. The linear voltage regulator integrated circuit has been tested at ambient temperatures from 25 to 200 °C with the input voltage varying from 10 to 30 V. A compensation method (pole swap) that extends the range of the system stability has been implemented and analyzed in detail. The simulated unity gain bandwidth can reach approximately 4 MHz when the load current is 200 mA and the measured transient response time is less than 150 nS when the load current is 50 mA and the ambient temperature is 200 °C.