A low power 12-bit 200-kS/s SAR ADC is proposed.This features a differential time domain comparator whose offset is cancelled by using a charge pump and a phase frequency detector instead of the preamplifiers usually ...A low power 12-bit 200-kS/s SAR ADC is proposed.This features a differential time domain comparator whose offset is cancelled by using a charge pump and a phase frequency detector instead of the preamplifiers usually needed in a high resolution comparator.The proposed ADC is manufactured in 0.18-μm CMOS technology and the measured SNR and SNDR are 62.5 dB and 59.3 dB,respectively,with a power consumption of 72μW at a 200-kS/s sampling rate.The device operates with a 1.8-V power supply and achieves a FOM of 477 fJ/conversion-step.展开更多
Objective To investgate the value of various parameters obtained from monoexponential,biexponential,and stretched exponential diffusion-weighted imaging models in the differential diagnosis of breast lesions.Methods A...Objective To investgate the value of various parameters obtained from monoexponential,biexponential,and stretched exponential diffusion-weighted imaging models in the differential diagnosis of breast lesions.Methods A retrospective study was performed in 54 patients with pathologically confirmed malignant tumors(n=30),benign lesions(n=34)and normal fibroglandular展开更多
基金Project supported by the National Natural Science Foundation of China(No.60876021)the State Key Laboratory Project,China (No.MS20080203)
文摘A low power 12-bit 200-kS/s SAR ADC is proposed.This features a differential time domain comparator whose offset is cancelled by using a charge pump and a phase frequency detector instead of the preamplifiers usually needed in a high resolution comparator.The proposed ADC is manufactured in 0.18-μm CMOS technology and the measured SNR and SNDR are 62.5 dB and 59.3 dB,respectively,with a power consumption of 72μW at a 200-kS/s sampling rate.The device operates with a 1.8-V power supply and achieves a FOM of 477 fJ/conversion-step.
文摘Objective To investgate the value of various parameters obtained from monoexponential,biexponential,and stretched exponential diffusion-weighted imaging models in the differential diagnosis of breast lesions.Methods A retrospective study was performed in 54 patients with pathologically confirmed malignant tumors(n=30),benign lesions(n=34)and normal fibroglandular
