• Title/Summary/Keyword: spread spectrum clock generator

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Design and Performance Analysis of sliding correlator digital DS-SS Transceiver (슬라이딩 상관기를 적용한 디지털 직접대역확산 송수신기의 설계 및 성능분석)

  • Kim, Seong-Cheol;Jin, Go-Whan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.9
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    • pp.1884-1891
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    • 2012
  • In this paper, we design the sliding correlator SS transceiver which supports short message service. We also analyze the PN code acquisition circuit that is essential for spread spectrum receiver. Using Maxplus II tool provided by altera Co., Ltd, we have designed PN code generator, and sliding correlator for PN code acquisition. Then, they have been made into FPGA by way of EPM7064SLC44-10 - a chip of Altera Co., Ltd. Additionally, we have designed delay clock circuit which is faster than the clock of Tx PN clock, designed switching circuit to control the clock rate and data demodulation circuit. The performance of the transceiver is evaluated from the experimental results. Especially, the performance of PN code acquisition accomplished by sliding correlator which is very important to evaluate spread spectrum receiver is evaluated with the comparison of the lock states.

A Design of PLL and Spread Spectrum Clock Generator for 2.7Gbps/1.62Gbps DisplayPort Transmitter (2.7Gbps/1.62Gbps DisplayPort 송신기용 PLL 및 확산대역 클록 발생기의 설계)

  • Kim, Young-Shin;Kim, Seong-Geun;Pu, Young-Gun;Hur, Jeong;Lee, Kang-Yoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.2
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    • pp.21-31
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    • 2010
  • This paper presents a design of PLL and SSCG for reducing the EMI effect at the electronic machinery and tools for DisplayPort application. This system is composed of the essential element of PLL and Charge-Pump2 and Reference Clock Divider to implement the SSCG operation. In this paper, 270MHz/162MHz dual-mode PLL that can provide 10-phase and 1.35GHz/810MHz PLL that can reduce the jitter are designed for 2.7Gbps/162Gbps DisplayPort application. The jitter can be reduced drastically by combining 270MHz/162MHz PLL with 2-stage 5 to 1 serializer and 1.35GHz PLL with 2 to 1 serializer. This paper propose the frequency divider topology which can share the divider between modes and guarantee the 50% duty ratio. And, the output current mismatch can be reduced by using the proposed charge-pump topology. It is implemented using 0.13 um CMOS process and die areas of 270MHz/162MHz PLL and 1.35GHz/810MHz PLL are $650um\;{\times}\;500um$ and $600um\;{\times}\;500um$, respectively. The VCO tuning range of 270 MHz/162 MHz PLL is 330 MHz and the phase noise is -114 dBc/Hz at 1 MHz offset. The measured SSCG down spread amplitude is 0.5% and modulation frequency is 31kHz. The total power consumption is 48mW.