A Low Area, Switched-Resistor Based Fractional-N Synthesizer Applied to a MEMS-Based Programmable Oscillator
| Autor: | Bruno W. Garlepp, Niveditha Arumugam, Shouvik Mukherjee, Sudhakar Pamarti, Cathy Lee, Michael H. Perrott, S Perumal, V Tsinker, Fred Lee, E G Hoffman, B T Soto |
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| Rok vydání: | 2010 |
| Předmět: |
Frequency synthesizer
Engineering business.industry Detector Electrical engineering Topology (electrical circuits) Switched capacitor Phase detector Phase-locked loop Voltage-controlled oscillator Direct digital synthesizer Hardware_INTEGRATEDCIRCUITS Electronic engineering Electrical and Electronic Engineering business |
| Zdroj: | IEEE Journal of Solid-State Circuits. 45:2566-2581 |
| ISSN: | 1558-173X 0018-9200 |
| DOI: | 10.1109/jssc.2010.2076570 |
| Popis: | MEMS-based oscillators have recently become a topic of interest as integrated alternatives are sought for quartz-based frequency references. When seeking a programmable solution, a key component of such systems is a low power, low area fractional-N synthesizer, which also provides a convenient path for compensating changes in the MEMS resonant frequency with temperature and process. We present several techniques enabling efficient implementation of this synthesizer, including a switched-resistor loop filter topology that avoids a charge pump and boosts effective resistance to save area, a high gain phase detector that lowers the impact of loop filter noise, and a switched capacitor frequency detector that provides initial frequency acquisition. The entire synthesizer with LC VCO occupies less than 0.36sq. mm in 0.18 m CMOS. Chip power consumption is 3.7 mA at 3.3 V supply (20 MHz output, no load). |
| Databáze: | OpenAIRE |
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