公开(公告)号：GB2265284B

公开(公告)日：1995-11-01

申请号：GB9305529

申请日：1993-03-17

Applicant: KOREA ELECTRONICS TELECOMM ,  KOREA TELECOMMUNICATION

Inventor： LEE BHUM CHEOL ,  PARK KWON CHUL ,  BAHK HANG GU

IPC: H03L7/089 ,  H03L7/093 ,  H03L7/107 ,  H03L7/14 ,  H04L7/00 ,  H04L7/033 ,  H03L7/087

Abstract: A bit synchronizer for NRZ data wherein a loop gain of a phase locked loop in the bit synchronizer is not varied sensitively to bit pattern and rate of the NRZ data and a voltage control led oscillator in the bit synchronizer oscillates synchronously with a multiple of a frequency of an external reference clock pulse even in the absence of NRZ data transitions or over a wide range of variation of a clock frequency of the voltage controlled oscillator, so that the NRZ data and clock can be recovered stably, According to the invention, the bit synchronizer comprises a phase comparator, a first gain controller, a frequency comparator, a second gain controller, a N-frequency divider, a low pass filter and a voltage controlled oscillator.

公开(公告)号：GB2265284A

公开(公告)日：1993-09-22

申请号：GB9305529

申请日：1993-03-17

Applicant: KOREA ELECTRONICS TELECOMM ,  KOREA TELECOMMUNICATION

Inventor： LEE BHUM CHEOL ,  PARK KWON CHUL ,  BAHK HANG GU

IPC: H03L7/089 ,  H03L7/093 ,  H03L7/107 ,  H03L7/14 ,  H04L7/00 ,  H04L7/033

Abstract: A bit synchronizer for NRZ data wherein a loop gain of a phase locked loop in the bit synchronizer is not varied sensitively to bit pattern and rate of the NRZ data and a voltage controlled oscillator in the bit synchronizer oscillates synchronously with a multiple of a frequency of an external reference clock pulse oven in the absence of NRZ data transitions or over a wide range of variation of a clock frequency of the voltage controlled oscillator, so that the NRZ data and clock can be recovered stably. According to the invention, the bit synchronizer comprises a phase comparator (21), a first gain controller (22), a frequency comparator (23), a second gain controller (24), a N-frequency divider (25), a low pass filter (26) and a voltage controlled oscillator (27). The first and second gain controllers limit the gains of the place and frequency comparators, respectively, to predetermined values.