A Low-Jitter Mixed-Mode DLL for Hign-Speed DRAM Applications

Abstract

This paper presents a salient clock deskewing method with a mixed-mode delay-locked loop (MDLL) for high-speed synchronous DRAM applications. The presented method not only solves the resolution problem of conventional digital deskewing circuits, but also improves the jitter performance to the le, el of well-designed analog deskewing circuits, while keeping the power consumption and locking speed of digital deskewing circuits. The whole deskewing circuit is fabricated in a 3.3-V 0.6-mu m triple-metal CMOS process and occupies a die area of 0.45 mm(2), Measured rms jitter is 6.38 ps, The power consumption of the entire chip, including I/O peripherals, is 33 mW at 200 MHz with a 3.3-V supply.