A Fast-settling Temperature-Insensitive Voltage Buffer

A fast-settling, temperature-insensitive voltage buffer is analyzed and designed. Class AB output stage in the buffer leads to high slew rate with relatively low power dissipation. The current switch not only sets the quiescent current of the output transistors, but also compensates the variation of Vth with temperature, which makes the buffer workable in a wide range of temperature. Simulation results show that the 0.1% settling time with 2V input step and 2OpF load is always less than 165ns when the temperature varies from 0°C to 100°C while the dissipation is less than 3mW. The die area without pads in 0.5um CMOS process is 350* 150um².