Title:
BIPOLAR/UNIPOLAR CONVERSION CIRCUIT
Document Type and Number:
Japanese Patent JP3528117
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a bipolar/unipolar conversion circuit which does not adjust clock extraction and whose circuit is made into a small scale.
SOLUTION: In the conversion circuit, a clock extraction unit 2 is constituted of a digital PLL circuit containing a phase comparator (FF) 2a comparing the phases of an RZ signal f1 obtained by converting an input signal (bipolar code signal) f0 by a bipolar/RZ converter 1 with a frequency-dividing clock signal f5 and outputting a phase comparison signal f21, a filter 2b filtering tub signal f21 and outputting a voltage control signal f22 and a voltage controlled oscillator (VCO) 2c oscillating/outputting a voltage control oscillation clock signal (unipolar code signal) f6 in accordance with a signal f22. A data reproduction part 3 is provided with a re-timing unit (FF) 3a generating a clock signal f7 from the signal fs obtained by frequency-dividing the signal f6 into 114 by a 1/4 frequency-dividing unit 4 and the signal f6 and a code converter (FF) 3b which code-converts the signal into an NRZ(non return to zero) signal with the signal f7.
Inventors:
Koike, Tsutomu
Souma, Kazutomo
Souma, Kazutomo
Application Number:
JP35038696A
Publication Date:
May 17, 2004
Filing Date:
December 27, 1996
Export Citation:
Assignee:
NEC ENG LTD
International Classes:
H03M5/16; H04L25/49; (IPC1-7): H04L25/49
Attorney, Agent or Firm:
机 昌彦 （外２名）