CDR CIRCUIT AND SEMICONDUCTOR DEVICE

• Main Authors: RYO ENDO, MITSUNORI TAKANASHI
• Format: Patent
• Language: English
• Published: 20.01.2016
• Subjects: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION, OR STABILISATIONOF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES; BASIC ELECTRONIC CIRCUITRY; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

The invention discloses a CDR circuit and a semiconductor device. Even if unexpected frequency fluctuation is generated in a oscillating circuit of CDR circuit due to temperature varies, a frequency pulling operation for a input data style is not updated to enable a oscillating clock signal to synchronize relative to the input data. A clock data recovery (CDR) circuit is provided with a circuit that updates a locked oscillation frequency, with a small loop gain, after phase lock based on a phase-locked loop circuit for a frequency-locked frequency is completed by a frequency-locked loop circuit or during a phase lock operation. Since the locked oscillation frequency is updated with a small loop gain, it is possible to correct a fluctuation in a frequency of an oscillation circuit in the frequency-locked loop circuit without oscillating a phase-locked loop undesirably even during a phase lock operation.