• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.899-905
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• 2017

This paper presents a reference-less dual loop clock and data recovery (CDR) circuit that supports a data rate of 2.496 Gb/s for the mobile industry processor interface (MIPI) M-PHY. An adaptive loop bandwidth scheme is used to implement the fast lock time maintaining a low time jitter. To this scheme, the proposed CDR consists of two loops for a frequency locked loop and a phase locked loop. The proposed 2.496 Gb/s reference-less dual loop CDR is designed using a 65 nm CMOS process with 1.2 V supply voltage. The simulated peak-to-peak jitter of output clock is 9.26 ps for the input data of 2.496 Gb/s pseudo-random binary sequence (PRBS) 15. The active area and power consumption of the implemented CDR are $470{\times}400{\mu}m^2$ and 6.49 mW, respectively.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.2
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• pp.130-134
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• 2008

This paper presents a clock and data recovery(CDR) using a quarter-rate technique. The proposed CDR helps reduce the VCO frequency and is thus advantageous for high speed application. It can achieve a low jitter operation and extend the pull-in range without a reference clock. The CDR consists of a quarter-rate bang-bang type phase detector(PD) quarter-rate frequency detector(QRFD), two charge pumps circuits(CPs), low pass filter(LPF) and a ring voltage controlled oscillator(VCO). The Proposed CDR has been fabricated in a standard $0.18{\mu}m$ 1P6M CMOS technology. It occupies an active area $1{\times}1mm^2$ and consumes 98 mW from a single 1.8 V supply.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.1
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• pp.82-86
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• 2009

This work is design of clock and data recovery circuit using system clock. This circuit is composed by PLL(Phase Locked Loop) to make system clock and data recovery circuit. The data recovery circuit using 1/4-rate phase picking Detector helps to reduce clock frequency. It is advantageous for high speed PLL. It can achieve a low jitter operation. The designed CDR(Clock and data recovery) has been designed in a standard $0.18{\mu}m$ 1P6M CMOS technology and an active area $1{\times}1mm^2$.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.5
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• pp.77-86
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• 2016

This paper describes a dual-mode reference-less CDR(Clock Data Recovery) operating at full / half-rate and its operation algorithm. Proposed reference-less CDR consists of a frequency detector, a phase detector, a charge pump, a loop filter, a voltage controlled oscillator, and a digital block. The frequency and phase detectors operate at both full / half-rate for dual-mode operation and especially the frequency detector is capable of detecting the difference between data rate and clock frequency in the dead zone of general frequency detectors. Dual-mode reference-less CDR with the proposed algorithm can recover the data and clock within 1.2-1.3 us and operates reliably at both full-rate (2.7 Gb/s) and half-rate (5.4 Gb/s) with 0.5-UI input jitter.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.2
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• pp.72-77
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• 2009

In this paper, a 3.2Gb/s clock and data recovery (CDR) circuit for a high-speed serial data communication without the reference clock is described This CDR circuit consists of 5 parts as Phase and frequency detector(PD and FD), multi-phase Voltage Controlled-Oscillator(VCO), Charge-pumps (CP) and external Loop-Filter(KF). It is adapted the PD and FD, which incorporates a half-rate bang-bang type oversampling PD and a half-rate FD that can improve pull-in range. The VCO consists of four fully differential delay cells with rail-to-rail current bias scheme that can increase the tuning range and tuning linearity. Each delay cell has output buffers as a full-swing generator and a duty-cycle mismatch compensation. This materialized CDR can achieve wide pull-in range without an extra reference clock and it can be also reduced chip area and power consumption effectively because there is no additional Phase Locked- Loop(PLL) for generating reference clock. The CDR circuit was designed for fabrication using 0.18um 1P6M CMOS process and total chip area excepted LF is $1{\times}1mm^2$. The pk-pk jitter of recovered clock is 26ps at 3.2Gb/s input data rate and total power consumes 63mW from 1.8V supply voltage according to simulation results. According to test result, the pk-pk jitter of recovered clock is 55ps at the same input data-rate and the reliable range of input data-rate is about from 2.4Gb/s to 3.4Gb/s.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.4
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• pp.39-45
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• 2015

In this paper, variable rate CDR(Clock and Data Recovery) circuit adopting blind oversampling architecture is presented. The clock recovery circuit is implemented by using wide range voltage controlled oscillator and band selection method and the data recovery circuit is designed to digital circuit used majority voting method in order to low power and small area. The designed low power variable clock and data recovery is implemented by wide range voltage controlled oscillator and digital data recovery circuit. The designed variable rate CDR is operated from 10 bps to 2 Mbps. The total power consumption is about 4.4mW at 1MHz clock. The supply voltage is 1.2V. The designed die area is $120{\mu}m{\times}75{\mu}m$ and this circuit is fabricated in $0.13{\mu}m$ CMOS process.

• Journal of IKEEE
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• v.23 no.3
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• pp.858-864
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• 2019

A clock system is proposed to eliminate data loss due to frequency difference between sensor nodes in a sensor utility network. The proposed clock system for each sensor node consists of a bust clock-data recovery (CDR) circuit, a digital phase-locked loop outputting a 32-phase clock, and a digital frequency synthesizer using a programmable open-loop fractional divider. A CMOS oscillator using an active inductor is used instead of a burst CDR circuit for the first sensor node. The proposed clock system is designed by using a 65 nm CMOS process with a 1.2 V supply voltage. When the frequency error between the sensor nodes is 1%, the proposed burst CDR has a time jitter of only 4.95 ns with a frequency multiplied by 64 for a data rate of 5 Mbps as the reference clock. Furthermore, the frequency change of the designed digital frequency synthesizer is performed within one period of the output clock in the frequency range of 100 kHz to 320 MHz.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.4
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• pp.39-50
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• 2011

In this paper, we presents a CDR circuit for $2^{nd}$-generation AiPi+, one of the Intra-panel Interface. The speed of the proposed clock and data recovery is increased to 1.25 Gbps compared with that of AiPi+. The DLL-based CDR architecture is used to generate the multi-phase clocks. We propose the simple scheme for frequency detector (FD) to mitigate the harmonic-locking and reduce the complexity. In addition, the duty cycle corrector that limits the maximum pulse width is used to avoid the problem of missing clock edges due to the mismatch between rising and falling time of VCDL's delay cells. The proposed CDR is implemented in 0.18 um technology with the supply voltage of 1.8 V. The active die area is $660\;{\mu}m\;{\times}\;250\;{\mu}m$, and supply voltage is 1.8 V. Peak-to-Peak jitter is less than 15 ps and the power consumption of the CDR except input buffer, equalizer, and de-serializer is 5.94 mW.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.10 s.352
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• pp.28-33
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• 2006

An integrated 3.125Gbps clock and data recovery (CDR) circuit is presented. The circuit does not need a reference clock. It has a phase and frequency detector (PFD), which incorporates a bang-bang type 4X oversampling PD and a rotational frequency detector (FD). It also has a ring oscillator type VCO with four delay stages and three zero-offset charge pumps. With a proposed PD and m, the tracking range of 24% can be achieved. Experimental results show that the circuit is capable of recovering clock and data at rates of 3.125Gbps with 0.18 um CMOS technology. The measured recovered clock jitter (p-p) is about 14ps. The CDR has 1.8volt single power supply. The power dissipation is about 140mW.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.1
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• pp.97-103
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• 2014

In this paper, a clock-data recovery using a 1/8-rate phase detector is proposed. The use of a conventional full or half-rate phase detector requires relatively higher frequency of a recovered clock, which is a burden on the design of a sampling circuit and a VCO. In this paper, a 1/8-rate phase detector is used to lower the frequency of the recovered clock and a linear equalizer is used as a input circuit of a phase detector to reduce the jitter of the recovered clock. A test chip fabricated in a 0.13-${\mu}m$ CMOS process is measured at 1.5-GHz for a 3-Gb/s PRBS input and 1.2-V power supply.