A current controlled CMOS output driver was designed by using a temperature-insensitive reference current generator. It eliminates the need for overdesign of the driver transistor size to meet the delay specification at high temperature. Comparison with the conventional CMOS output driver with the same transistor size showed that the ground bounce noise was reduced by 2.5 times and the delay time was increased by 1.4 times, at 25 for 50pF load. The temperature variations of the DC pull-up and pull-down currents of the new output driver were 4% within the temperature range from -15 to 125 compared to the variations of 40 and 60% for pull-up and pull-down respectively for the conventional output driver. The temperature insensitivity of the reference current generator was achieved by multiplying two current components. one which is proportional to mobility and the other which is inversely proportional to mobility, by using a CMOS square root circuit. The temperature variation of the DC output current of the reference current generator alone was 0.77% within the entire temperature range from -15 to 125.

A fully differential folded cascode CMOS OP amp is combined with an adaptive bias OTA to increase the slew rate, and a continuous-time CMFB circuit with a push-pull type combination of a NMOS input and a PMOS input differential amplifiers is used to maximize the output voltage swing. The fabricated OP amp using a 0.8 µm digital CMOS process gives more than three times improvement in slew rate with a 15% increase in DC power consumption and a 7.5% increase in chip area compared to the conventional OP amp fabricated on the same die. The output voltage swing was measured to be -0.75 V -0.7 V at the supply voltage of +/-1.2 V.