A programmable multi-modulus frequency divider is designed and implemented in a 0. 35μm CMOS process. The multi-modulus frequency divider is a single chip with two dividers in series,which are divided by 4 or 5 presc...A programmable multi-modulus frequency divider is designed and implemented in a 0. 35μm CMOS process. The multi-modulus frequency divider is a single chip with two dividers in series,which are divided by 4 or 5 prescaler and by 128-255 multi-modulus frequency divider. In the circuit design, power and speed trade-offs are analyzed for the prescaler, and power optimization techniques are used according to the input frequency of each divider cell for the 128-255 multimodulus frequency divider. The chip is designed with ESD protected I/O PAD. The dividers chain can work as high as 2.4GHz with a single ended input signal and beyond 2.6GHz with differential input signals. The dual-modulus prescaler consumes 11mA of current while the 128-255 multi-modulus frequency divider consumes 17mA of current with a 3.3V power supply. The core area of the die without PAD is 0.65mm × 0.3mm. This programmable multi-modulus frequency divider can be used for 2.4GHz ISM band PLL-based frequency synthesizers. To our knowledge, this is the first reported multi-modulus frequency divider with this structure in China.展开更多
A 900MHz CMOS PLL/frequency synthesizer using current-adjustable charge-pump circuit and on-chip loop filter with initialization circuit is presented.The charge-pump current is insensitive to the changes of temperatur...A 900MHz CMOS PLL/frequency synthesizer using current-adjustable charge-pump circuit and on-chip loop filter with initialization circuit is presented.The charge-pump current is insensitive to the changes of temperature and power supply.The value of the charge-pump current can be changed by switches,which are controlled by external signals.Thus the performance of the PLL,such as loop bandwidth,can be changed with the change of the charge-pump current.The loop filter initialization circuit can speed up the PLL when the power is on.A multi-modulus prescaler is used to fulfill the frequency synthesis.The circuit is designed using 0.18μm,1.8V,1P6M standard digital CMOS process.展开更多
A pulse swallowing frequency divider with low power and compact structure is presented.One of the DFFs in the divided by 2/3 prescaier is controlled by the modulus control signal,and automatically powered off when it ...A pulse swallowing frequency divider with low power and compact structure is presented.One of the DFFs in the divided by 2/3 prescaier is controlled by the modulus control signal,and automatically powered off when it has no contribution to the operation of the prescaier.The DFFs in the program counter and the swallow counter are shared to compose a compact structure,which reduces the power consumption further.The proposed multi-modulus frequency divider was implemented in a standard 65 nm CMOS process with an area of 28×22μm;.The power consumption of the divider is 0.6 mW under 1.2 V supply voltage when operating at 988 MHz.展开更多
文摘A programmable multi-modulus frequency divider is designed and implemented in a 0. 35μm CMOS process. The multi-modulus frequency divider is a single chip with two dividers in series,which are divided by 4 or 5 prescaler and by 128-255 multi-modulus frequency divider. In the circuit design, power and speed trade-offs are analyzed for the prescaler, and power optimization techniques are used according to the input frequency of each divider cell for the 128-255 multimodulus frequency divider. The chip is designed with ESD protected I/O PAD. The dividers chain can work as high as 2.4GHz with a single ended input signal and beyond 2.6GHz with differential input signals. The dual-modulus prescaler consumes 11mA of current while the 128-255 multi-modulus frequency divider consumes 17mA of current with a 3.3V power supply. The core area of the die without PAD is 0.65mm × 0.3mm. This programmable multi-modulus frequency divider can be used for 2.4GHz ISM band PLL-based frequency synthesizers. To our knowledge, this is the first reported multi-modulus frequency divider with this structure in China.
文摘A 900MHz CMOS PLL/frequency synthesizer using current-adjustable charge-pump circuit and on-chip loop filter with initialization circuit is presented.The charge-pump current is insensitive to the changes of temperature and power supply.The value of the charge-pump current can be changed by switches,which are controlled by external signals.Thus the performance of the PLL,such as loop bandwidth,can be changed with the change of the charge-pump current.The loop filter initialization circuit can speed up the PLL when the power is on.A multi-modulus prescaler is used to fulfill the frequency synthesis.The circuit is designed using 0.18μm,1.8V,1P6M standard digital CMOS process.
基金supported by the Major State Basic Research Development Program of China(No.2010CB327403)the National Natural Science Foundation of China(No.61001066)
文摘A pulse swallowing frequency divider with low power and compact structure is presented.One of the DFFs in the divided by 2/3 prescaier is controlled by the modulus control signal,and automatically powered off when it has no contribution to the operation of the prescaier.The DFFs in the program counter and the swallow counter are shared to compose a compact structure,which reduces the power consumption further.The proposed multi-modulus frequency divider was implemented in a standard 65 nm CMOS process with an area of 28×22μm;.The power consumption of the divider is 0.6 mW under 1.2 V supply voltage when operating at 988 MHz.
