Analyzing the influence on Q factor, which was caused by the parasitic effect in a CMOS RF on chip integrated inductor, a concise method to increase the Q factor has been obtained when optimizing the layout parameter....Analyzing the influence on Q factor, which was caused by the parasitic effect in a CMOS RF on chip integrated inductor, a concise method to increase the Q factor has been obtained when optimizing the layout parameter. Using this method, the Q factor of 7.9 can be achieved in a 5nH inductor (operating frequency is 2GHz) while the errors in inductance are less than 0.5% compared with the aimed values. It is proved by experiments that this method can guarantee the sufficient accuracy but require less computation time. Therefore, it is of great use for the design of the inductor in CMOS RF IC’s.展开更多
Radiation-induced inter-device leakage is studied using an analytical model and TCAD simulation. There were some different opinions in understanding the process of defect build-up in trench oxide and parasitic leakage...Radiation-induced inter-device leakage is studied using an analytical model and TCAD simulation. There were some different opinions in understanding the process of defect build-up in trench oxide and parasitic leakage path turning on from earlier studies.To reanalyze this problem and make it beyond argument,every possible variable is considered using theoretical analysis,not just the change of electric field or oxide thickness independently. Among all possible inter-device leakage paths,parasitic structures with N-well as both drain and source are comparatively more sensitive to the total dose effect when a voltage discrepancy exists between the drain and source region.Since N-well regions are commonly connected to the same power supply,these kinds of structures will not be a problem in a real CMOS integrated circuit.Generally speaking,conduction paths of inter-device leakage existing in a real integrated circuit and under real electrical circumstances are not very sensitive to the total ionizing dose effect.展开更多
A CMOS compatible P＋/Nwell/Psub double junction photodiode pixel was proposed, which can effi- ciently detect fluorescence from CsI（T1） scintillation in an X-ray sensor. Photoelectric and spectral responses of P＋/...A CMOS compatible P＋/Nwell/Psub double junction photodiode pixel was proposed, which can effi- ciently detect fluorescence from CsI（T1） scintillation in an X-ray sensor. Photoelectric and spectral responses of P＋/Nwell, NweE1/Psub and P＋/Nwell/Psub photodiodes were analyzed and modeled. Simulation results show P＋/Nweu/Psub photodiode has larger photocurrent than P＋/Nwetl photodiode and Nweu/Psub photodiode, and its spectral response is more in accordance with CsI（T1） fluorescence spectrum. Improved P＋/Nweu/Psub photodiode detecting CsI（T1） fluorescence was designed in CSMC 0.5 #m CMOS process, CTIA （capacitive transimpedance amplifier） architecture was used to readout photocurrent signal. CMOS X-ray sensor IC prototype contains 8 × 8 pixel array and pixel pitch is 100 × 100 μm2. Testing results show the dark current of the improved P＋/Nwell/Psub photodiode （6.5 pA） is less than that of P＋/Nwell and P＋/Nwell/Psub photodiodes （13 pA and 11 pA respectively）. The sen- sitivity of P＋/Nwell/Psub photodiode is about 20 pA/lux under white LED. The spectrum response of P＋/Nwell/Psub photodiode ranges from 400 nm to 800 nm with a peak at 532 nm, which is in accordance with the fluorescence spectrum of Csl（T1） in an indirect X-ray sensor. Preliminary testing results show the sensitivity of X-ray sensor IC under Cu target X-ray is about 0.21 V.m^2/W or 5097e-/pixel @ 8.05 keV considering the pixel size, integration time and average energy of X-ray photons.展开更多
This paper proposes a direct injection-locked frequency divider（ILFD） with a wide locking range in the Ka-band. A complementary cross-coupled architecture is used to enhance the overdriving voltage of the switch tra...This paper proposes a direct injection-locked frequency divider（ILFD） with a wide locking range in the Ka-band. A complementary cross-coupled architecture is used to enhance the overdriving voltage of the switch transistor so that the divider locking range is extended efficiently. New insights into the locking range and output power are proposed. A new method to analyze and optimize the injection sensitivity is presented and a layout technique to reduce the parasitics of the cross-coupled transistors is applied to decrease the frequency shift and the locking range degradation. The circuit is designed in a standard 90-nm CMOS process. The total locking range of the ILFD is 43.8% at 34.5 GHz with an incident power of –3.5 dBm. The divider IC consumes 3.6 mW of power at the supply voltage of 1.2 V. The chip area including the pads is 0.50.5 mm2.展开更多
文摘Analyzing the influence on Q factor, which was caused by the parasitic effect in a CMOS RF on chip integrated inductor, a concise method to increase the Q factor has been obtained when optimizing the layout parameter. Using this method, the Q factor of 7.9 can be achieved in a 5nH inductor (operating frequency is 2GHz) while the errors in inductance are less than 0.5% compared with the aimed values. It is proved by experiments that this method can guarantee the sufficient accuracy but require less computation time. Therefore, it is of great use for the design of the inductor in CMOS RF IC’s.
文摘Radiation-induced inter-device leakage is studied using an analytical model and TCAD simulation. There were some different opinions in understanding the process of defect build-up in trench oxide and parasitic leakage path turning on from earlier studies.To reanalyze this problem and make it beyond argument,every possible variable is considered using theoretical analysis,not just the change of electric field or oxide thickness independently. Among all possible inter-device leakage paths,parasitic structures with N-well as both drain and source are comparatively more sensitive to the total dose effect when a voltage discrepancy exists between the drain and source region.Since N-well regions are commonly connected to the same power supply,these kinds of structures will not be a problem in a real CMOS integrated circuit.Generally speaking,conduction paths of inter-device leakage existing in a real integrated circuit and under real electrical circumstances are not very sensitive to the total ionizing dose effect.
基金supported by the National Natural Science Foundation of China(No.61076075)the Natural Science Foundation of Zhejiang Province(No.Y1100287)
文摘A CMOS compatible P＋/Nwell/Psub double junction photodiode pixel was proposed, which can effi- ciently detect fluorescence from CsI（T1） scintillation in an X-ray sensor. Photoelectric and spectral responses of P＋/Nwell, NweE1/Psub and P＋/Nwell/Psub photodiodes were analyzed and modeled. Simulation results show P＋/Nweu/Psub photodiode has larger photocurrent than P＋/Nwetl photodiode and Nweu/Psub photodiode, and its spectral response is more in accordance with CsI（T1） fluorescence spectrum. Improved P＋/Nweu/Psub photodiode detecting CsI（T1） fluorescence was designed in CSMC 0.5 #m CMOS process, CTIA （capacitive transimpedance amplifier） architecture was used to readout photocurrent signal. CMOS X-ray sensor IC prototype contains 8 × 8 pixel array and pixel pitch is 100 × 100 μm2. Testing results show the dark current of the improved P＋/Nwell/Psub photodiode （6.5 pA） is less than that of P＋/Nwell and P＋/Nwell/Psub photodiodes （13 pA and 11 pA respectively）. The sen- sitivity of P＋/Nwell/Psub photodiode is about 20 pA/lux under white LED. The spectrum response of P＋/Nwell/Psub photodiode ranges from 400 nm to 800 nm with a peak at 532 nm, which is in accordance with the fluorescence spectrum of Csl（T1） in an indirect X-ray sensor. Preliminary testing results show the sensitivity of X-ray sensor IC under Cu target X-ray is about 0.21 V.m^2/W or 5097e-/pixel @ 8.05 keV considering the pixel size, integration time and average energy of X-ray photons.
基金Project supported by the National Basic Research Program(No.2010CB327404)the National High Technology Researchand Development Program of China(No.2011AA10305)+1 种基金the International Cooperation Projects in Science and Technology(No.2011DFA11310)the National Natural Science Foundation of China(Nos.60901012,61106024)
文摘This paper proposes a direct injection-locked frequency divider（ILFD） with a wide locking range in the Ka-band. A complementary cross-coupled architecture is used to enhance the overdriving voltage of the switch transistor so that the divider locking range is extended efficiently. New insights into the locking range and output power are proposed. A new method to analyze and optimize the injection sensitivity is presented and a layout technique to reduce the parasitics of the cross-coupled transistors is applied to decrease the frequency shift and the locking range degradation. The circuit is designed in a standard 90-nm CMOS process. The total locking range of the ILFD is 43.8% at 34.5 GHz with an incident power of –3.5 dBm. The divider IC consumes 3.6 mW of power at the supply voltage of 1.2 V. The chip area including the pads is 0.50.5 mm2.
