Spread Spectrum Clock Generator With Delay Cell Array to Reduce Electromagnetic Interference

2005 ◽  
Vol 47 (4) ◽  
pp. 908-920 ◽  
Author(s):  
J. Kim ◽  
D.G. Kam ◽  
P.J. Jun ◽  
J. Kim
Keyword(s):  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Clock Generator ◽  
Cell Array ◽  
Delay Cell

scholarly journals Design of double ring lock ring in extensible frequency clock generator chip

2021 ◽  
Vol 2137 (1) ◽  
pp. 012041
Author(s):  
Chao Xu ◽  
Yumeng Xie ◽  
Yuan Zhou
Keyword(s):  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Phase Locked Loop ◽  
Center Frequency ◽  
Good Effect ◽  
Clock Generator ◽  
Clock Frequency ◽  
Noise Interference ◽  
Main Loop ◽  
Secondary Loop

Abstract With the continuous development of computer technology and the continuous improvement of interface data rate, the clock frequency has reached the demand of several gigahertz, which makes the electromagnetic interference problem very serious. Spread spectrum clock is an effective method to reduce electromagnetic interference of digital chips. Therefore, this paper designs a double-loop phase-locked loop that can spread spectrum and has strong anti-electromagnetic noise interference ability. The designed dual-loop phase-locked loop can be used in the clock generator chip. The overall structure of the circuit consists of a main loop and a secondary loop. The main loop is an adjustable phase-locked loop circuit that can provide an output with a center frequency of 500MHz. The secondary loop can realize the spread spectrum function by charging and discharging the filter capacitor of the main loop loop, and at the same time, the spreading depth can be set by the feedback based on the frequency division. The dual-loop phase-locked loop designed in this paper has a good effect in spread spectrum and anti-electromagnetic interference noise.

scholarly journals A Regulated Pulse Current Driver with Spread Spectrum Clock Generator †

Electronics ◽  
2021 ◽  
Vol 10 (21) ◽  
pp. 2661
Author(s):  
Ming-Shian Lin
Keyword(s):  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Peak Power ◽  
Pulse Current ◽  
Power Level ◽  
Consumer Electronics ◽  
Voltage Controlled Oscillator ◽  
Clock Generator ◽  
Electronic Components ◽  
Triangular Wave

This paper presents a regulated pulse current driver with a spread spectrum clock generator (SSCG) to lower the electromagnetic interference (EMI) effect. An SSCG is used and implemented by applying a triangular wave to modulate a voltage-controlled oscillator (VCO). The results show a 7 dBm reduction in the peak power level with a frequency deviation of 10%, demonstrating that the dominate harmonic is spread and distributed to adjacent frequencies, and the magnitude of harmonics is significantly reduced. The results demonstrate that the driver with a spread spectrum clock generator would help to reduce interference in sensitive electronic components and be suitable for portable consumer electronics applications.

A 3.5 GHz Spread-Spectrum Clock Generator With a Memoryless Newton-Raphson Modulation Profile

2012 ◽  
Vol 47 (5) ◽  
pp. 1199-1208 ◽  
Author(s):  
Sewook Hwang ◽  
Minyoung Song ◽  
Young-Ho Kwak ◽  
Inhwa Jung ◽  
Chulwoo Kim
Keyword(s):  
Spread Spectrum ◽  
Clock Generator ◽  
Newton Raphson

scholarly journals A spread-spectrum clock generator with direct VCO modulation in open-loop

2017 ◽  
Vol 14 (17) ◽  
pp. 20170417-20170417
Author(s):  
Hyunsun Mo ◽  
Daejeong Kim
Keyword(s):  
Spread Spectrum ◽  
Open Loop ◽  
Clock Generator

scholarly journals A Low EMI DC-DC Buck Converter with a Triangular Spread-Spectrum Mechanism

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 856
Author(s):  
Jing-Yuan Lin ◽  
Yi-Chieh Hsu ◽  
Yo-Da Lin
Keyword(s):  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Output Voltage ◽  
Buck Converter ◽  
Circuit Board ◽  
System Stability ◽  
Maximum Efficiency ◽  
Load Current ◽  
Voltage Range ◽  
Switching Regulators

In this paper, a triangular spread-spectrum mechanism is proposed to suppress the electromagnetic interference (EMI) of a DC-DC buck converter. The proposed triangular spread-spectrum mechanism, which is implemented in the chip, can avoid modifying the printed circuit board of switching regulators. In addition, a lower ripple of output voltage of switching regulators and a better system stability can be realized by the inductive DC resistance (DCR) current sensing circuit. The chip is fabricated by using TSMC 0.18-μm 1P6M CMOS technology. The chip area including PADs is 1.2 × 1.15 mm2. The input voltage range is 2.7~3.3 V and the output voltage is 1.8 V. The maximum load current is 700 mA. The off-chip inductor and capacitor are 3.3 μH and 10 μF, respectively. The experimental results demonstrate that the maximum spur of the proposed DC-DC buck converter with the triangular spread-spectrum mechanism improves to 14dBm. Moreover, the transient recovery time of step-up and step-down loads are both 5 μs. The measured maximum efficiency is 94% when the load current is 200 mA.

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