A high-speed and high-resolution CMOS comparator with three-stage preamplifier  

作　　者：江利 许维胜 余有灵 

机构地区：[1]School of Electronics and Information,Tongji University [2]Research Institute of Semiconductor,Tongji University

出　　处：《Journal of Semiconductors》2010年第4期80-84,共5页半导体学报（英文版）

基　　金：supported by the National High Technology Research and Development Program of China(No.2006AA05Z211).

摘　　要：The accuracy of A/D and D/A converters depend largely upon their inner comparators. To guarantee 12-bit high resolution for an A/D converter, a precise CMOS comparator consisting of a three-stage differential preamplifier together with a positive feedback latch is proposed. Circuit structure, gain, the principle of input offset voltage storage and latching time constant for the comparator will be analyzed and optimized in this article. With 0.5μm HYNIX mixed signal technology, the simulation result shows that the circuit has a precision of 400 μV at 20 MHz. The test result shows that the circuit has a precision of 600μV at 16 MHz, and dissipates only 78μW of power dissipation at 5 V. The size of the chip is 210 × 180μm^2. The comparator has been successfully used in a 10 MSPS 12-bit A/D converter. The circuit can be also used in a less than 13-bit A/D converter.The accuracy of A/D and D/A converters depend largely upon their inner comparators. To guarantee 12-bit high resolution for an A/D converter, a precise CMOS comparator consisting of a three-stage differential preamplifier together with a positive feedback latch is proposed. Circuit structure, gain, the principle of input offset voltage storage and latching time constant for the comparator will be analyzed and optimized in this article. With 0.5μm HYNIX mixed signal technology, the simulation result shows that the circuit has a precision of 400 μV at 20 MHz. The test result shows that the circuit has a precision of 600μV at 16 MHz, and dissipates only 78μW of power dissipation at 5 V. The size of the chip is 210 × 180μm^2. The comparator has been successfully used in a 10 MSPS 12-bit A/D converter. The circuit can be also used in a less than 13-bit A/D converter.

关 键 词：high speed comparator CMOS comparator input offset storage LATCH 

分 类 号：TN722.71[电子电信—电路与系统] TN432