1,643 research outputs found

    A GHz Full-Division-Range Programmable Divider with Output Duty-Cycle Improved

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    [[sponsorship]]Test Technology Technical Council (TTTC), IEEE Computer Society ; Faculty of Information Technology, Brno University of Technology[[conferencetype]]國際[[conferencedate]]20130408~20130410[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Karlovy Vary (Carlsbad), Czech Republi

    A Programmable Frequency Divider Having a Wide Division Ratio Range, and Close-to-50% Output Duty-Cycle

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    In Radio Frequency (RF) integrated circuit design field, programmable dividers are getting more and more attentions in recent years. A programmable frequency divider can divide an input frequency by programmable ratios [1]. It is a key component of a frequency synthesizer. It also can be used to generate variable clock-signals for: switched-capacitor filters (SCFs), digital systems with different power-states, as well as multiple clock-signals on the same system-on-a-chip (SOC). These circuits need high performance programmable frequency dividers, operating at high frequencies and having wide division ratio ranges, with binary division ratio controls and 50% output duty-cycle. Different types of programmable frequency dividers are reviewed and compared. A programmable frequency divider with a wide division ratio range of (8 ~ 524287) has been reported [2]. Because the output duty-cycle of this reported divider is far from 50%, the circuit in [2] has very limited applications. The proposed design solves this problem, without compromising other advantages of the design in [2]. The proposed design is fabricated in a 0.18-μm RF CMOS process. Test results show that the output duty-cycle is 50% when the division ratio is an even number. The duty-cycle is 44.4% when the division ratio is 9. The output duty-cycle becomes closer to 50% when the division ratio is an increasing odd number. For each division ratio, the output duty-cycle remains constant, with different input frequencies from GHz down to kHz ranges, with different temperatures and power supply voltages. This thesis provides an explanation of the design details and test results. A Phase Locked-Loop (PLL) based frequency synthesizer can generate different output frequencies. A programmable frequency divider is an important component of this type of PLL. Since bandwidth is expensive, it is preferred to reduce the frequency channel distance of a frequency synthesizer. Using a fractional programmable divider, the frequency channel distance of a PLL can be reduced, without reducing the reference frequency or increasing the settling time of the PLL. A frequency synthesizer with a programmable fractional divider is designed and fabricated. A brief description of the PLL design and test results are presented in this dissertation

    A Low Noise Sub-Sampling PLL in Which Divider Noise Is Eliminated and PD-CP Noise Is not multiplied by N^2

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    This paper presents a 2.2-GHz low jitter sub-sampling based PLL. It uses a phase-detector/charge-pump (PD/CP)that sub-samples the VCO output with the reference clock. In contrast to what happens in a classical PLL, the PD/CP noise is not multiplied by N2 in this sub-sampling PLL, resulting in a low noise contribution from the PD/CP. Moreover, no frequency divider is needed in the locked state and hence divider noise and power can be eliminated. An added frequency locked loop guarantees correct frequency locking without degenerating jitter performance when in lock. The PLL is implemented in a standard 0.18- m CMOS process. It consumes 4.2 mA from a 1.8 V supply and occupies an active area of 0.4 X 0.45 m

    Design and implementation of frequency synthesizers for 3-10 ghz mulitband ofdm uwb communication

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    The allocation of frequency spectrum by the FCC for Ultra Wideband (UWB) communications in the 3.1-10.6 GHz has paved the path for very high data rate Gb/s wireless communications. Frequency synthesis in these communication systems involves great challenges such as high frequency and wideband operation in addition to stringent requirements on frequency hopping time and coexistence with other wireless standards. This research proposes frequency generation schemes for such radio systems and their integrated implementations in silicon based technologies. Special emphasis is placed on efficient frequency planning and other system level considerations for building compact and practical systems for carrier frequency generation in an integrated UWB radio. This work proposes a frequency band plan for multiband OFDM based UWB radios in the 3.1-10.6 GHz range. Based on this frequency plan, two 11-band frequency synthesizers are designed, implemented and tested making them one of the first frequency synthesizers for UWB covering 78% of the licensed spectrum. The circuits are implemented in 0.25µm SiGe BiCMOS and the architectures are based on a single VCO at a fixed frequency followed by an array of dividers, multiplexers and single sideband (SSB) mixers to generate the 11 required bands in quadrature with fast hopping in much less than 9.5 ns. One of the synthesizers is integrated and tested as part of a 3-10 GHz packaged receiver. It draws 80 mA current from a 2.5 V supply and occupies an area of 2.25 mm2. Finally, an architecture for a UWB synthesizer is proposed that is based on a single multiband quadrature VCO, a programmable integer divider with 50% duty cycle and a single sideband mixer. A frequency band plan is proposed that greatly relaxes the tuning range requirement of the multiband VCO and leads to a very digitally intensive architecture for wideband frequency synthesis suitable for implementation in deep submicron CMOS processes. A design in 130nm CMOS occupies less than 1 mm2 while consuming 90 mW. This architecture provides an efficient solution in terms of area and power consumption with very low complexity

    52-GHz Millimetre-Wave PLL Synthesizer

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    A programmable CMOS decimator for sigma-delta analog-to-digital converter and charge pump circuits

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    PROGRAMMABLE DECIMATOR FOR SIGMA-DELTA ANALOG-TO-DIGITAL CONVERTER: In this work a programmable decimator design has been presented in 1.5 μm n-well CMOS process for integration with an existing modulator to form a sigma-delta analog-to-digital converter (ADC). The decimator is implemented using a second order Cascaded Integrator Comb (CIC) filter and can be programmed to work with two different oversampling ratios of 64 and 16. The input to the decimator is provided from a first order modulator. With oversampling ratios of 64 and 16, an output resolution of 10-bit and 7-bit, respectively are achieved for the ADC. The ADC can be operated with an oversampling clock frequency of up to 8 MHz and with an input signal bandwidth of up to 65 KHz. An in-built clock divider circuit has been designed which generates two output clocks whose frequencies are equal to the input clock frequency divided by the oversampling ratios 64 and 16. CHARGE PUMP CIRCUITS: The charge pump CMOS circuits are presented which are designed based on a new technique of internal clock voltage boosting. Four and six-stage charge pumps are implemented in 1.5 μm n-well CMOS process. The charge pump circuits can be operated in 1.2 V - 3 V power supply voltage range. Outputs of 12.5 V and 17.8 V are measured from four and six-stage charge pumps, respectively with a 3 V power supply. The charge pump circuits can also be used to generate clock voltages higher than the input clock voltage. In the present design, clock voltages of 8 V and 11 V have been generated from four-stage and six-stage charge pumps, respectively which are nearly 2.5 and 4 times the input clock voltage of 3 V. The technique of boosting the clock internally has been applied in implementation of a revised version of battery powered Bio-implantable Electrical Stimulation System (BESS) integrated circuit

    A PLL frequency synthesizer for a 300 MHz high temperature transceiver realized in 0.5um SOS technology

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    This thesis presents a study of the design of a phase-lock loop (PLL) system, including specific designs for a voltage-controlled oscillator and programmable frequency divider, implemented in a 0.5μm silicon-on-sapphire CMOS technology. The system is designed for use as a frequency synthesizer in a high-temperature transceiver. Several issues relating to high-temperature applications as well as the overall system architecture are presented. Principles of the PLL system are described, and critical design considerations are discussed. The designs of the VCO and programmable divider are described and analyzed in detail. A brief discussion of the design and analysis of other PLL components is presented. Prototyping and testing procedures are discussed and the results of the prototyped circuits are evaluated. Finally, a summary of the work is presented along with insights gained toward future research

    A GHz-range, High-resolution Multi-modulus Prescaler for Extreme Environment Applications

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    The generation of a precise, low-noise, reliable clock source is critical to developing mixed-signal and digital electronic systems. The applications of such a clock source are greatly expanded if the clock source can be configured to output different clock frequencies. The phase-locked loop (PLL) is a well-documented architecture for realizing this configurable clock source. Principle to the configurability of a PLL is a multi-modulus divider. The resolution of this divider (or prescaler) dictates the resolution of the configurable PLL output frequency. In integrated PLL designs, such a multi-modulus prescaler is usually sourced from a GHz-range voltage-controlled oscillator. Therefore, a fully-integrated PLL ASIC requires the development of a high-speed, high-resolution multi-modulus prescaler. The design challenges associated with developing such a prescaler are compounded when the application requires the device to operate in an extreme environment. In these extreme environments (often extra-terrestrial), wide temperature ranges and radiation effects can adversely affect the operation of electronic systems. Even more problematic is that extreme temperatures and ionizing radiation can cause permanent damage to electronic devices. Typical commercial-off-the-shelf (COTS) components are not able withstand such an environment, and any electronics operating in these extreme conditions must be designed to accommodate such operation. This dissertation describes the development of a high-speed, high-resolution, multi-modulus prescaler capable of operating in an extreme environment. This prescaler has been developed using current-mode logic (CML) on a 180-nm silicon-germanium (SiGe) BiCMOS process. The prescaler is capable of operating up to at least 5.4 GHz over a division range of 16-48 with a total of 27 configurable moduli. The prescaler is designed to provide excellent ionizing radiation hardness, single-event latch-up (SEL) immunity, and single-event upset (SEU) resistance over a temperature range of −180°C to 125°C
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