Journal of Xidian University ›› 2022, Vol. 49 ›› Issue (1): 194-201.doi: 10.19665/j.issn1001-2400.2022.01.020

• Information and Communications Engineering • Previous Articles     Next Articles

Wide-range and high-accuracy four-phase DLL with the adaptive-bandwidth scheme

YANG Xue1,2(),LIU Fei1(),HUO Zongliang1()   

  1. 1. Institute of Microelectronics,Chinese Academy of Sciences,Beijing 100029,China
    2. University of Chinese Academy of Sciences,Beijing 100864,China
  • Received:2020-11-20 Online:2022-02-20 Published:2022-04-27

Abstract:

This paper presents a four-phase output delay locked loop (DLL) with one adaptive bandwidth delay chain structure,which is suitable for the clock generation of the NAND Flash high-speed interface circuit meeting the ONFI 4.2 international protocol standard.In order to solve the problem of the limited delay time of the traditional delay chain in a wide frequency range,a configurable delay chain circuit structure is proposed,which can select the appropriated delay units in different frequency bands so that the operating frequency range of DLL is extended and the lock accuracy is maintained.In addition,an adaptive control circuit based on the frequency detector is proposed,which can track the input clock frequency,automatically configure the delay chain,and realize the adaptive bandwidth of the DLL.In the SMIC 28nm CMOS process,the DLL circuit is designed.Simulation results show that the locking range of the DLL is [22 MHz,1.6 GHz] with the maximum locking accuracy being 17 ps at the 25℃/0.9 V power supply and typical process corner.

Key words: delay locked loop, NAND Flash high-speed interface, wide-range, high accuracy

CLC Number: 

  • TN911.8