Abstract—An accurate CMOS current source for current-mode low-voltage differential transmitter drivers has been designed and fabricated. It is composed of binary weighted current mirrors with built-in self-calibration circuits. The proposed self-measurement and calibration circuits can calibrate upon the collective effects of different error contributors due to process, power supply, and temperature variations. The design has been fabricated in standard 0.35- m CMOS technology. Measurement results show that the differential output voltage can be self-calibrated to 1 % accuracy with 16 % reference current variation, 60 % power supply variation, or 13 % load resistance variation, respectively. Index Terms—Built-in self-measurement, CMOS integrated circuits, current-mode transmitter driver, low-voltage, self-calibration. I.