Adaptive driver with automatic sense and calibration in CMOS 40LP

Dynamically calibrated driver block is presented which automatically adapts its termination resistance to the channel´s impedance. The driver senses the channel and calibrates to its characteristic impedance anywhere between 30 - 120 ohms. This circuit functions successfully for a minimum propagation delay of 500 ps on the channel. Results on the STM CMOS 40LP process confirm the driver´s impedance match to that of the line with an accuracy of +/- 8% with +/-3σ variation in the process, +/- 10% voltage spread at 2.5V and temperature variation range of - 40 to 125 degrees centigrade.