A high speed/power ratio continuous-time CMOS current comparator

Current comparator is a fundamental component of current-mode circuits. A new high-performance continuous-time CMOS current comparator is proposed in this paper, which comprises one CMOS complementary amplifier, two resistive-load amplifiers and two CMOS inverters. A MOS resistor is used as the CMOS complementary amplifier's negative feedback. Because the voltage swings of the CMOS complementary amplifier are reduced by low input and output resistances, the delay time of the current comparator is shortened. Its power consumption is reduced by the resistive-load amplifiers. Simulation results based on 1.2 /spl mu/m CMOS technology parameters show the speed/power ratio of this new current comparator is better than existing high-performance current comparators. Besides, the new current comparator occupies small area and is process-robust, so it is suitable for high-speed and low-power applications.