Perimeter Gated Single Photon Avalanche Diodes in Sub-Micron and Deep-Submicron CMOS Processes

A perimeter gated SPAD (PGSPAD), a SPAD with an additional gate terminal, prevents premature perimeter breakdown in standard CMOS SPADs. At the same time, a PGSPAD takes advantage of the benefits of standard CMOS. This includes low cost and high electronics integration capability. In this work, we simulate the effect of the applied voltage at the perimeter gate to develop a consistent electric field distribution at the junction through physical device simulation. Additionally, the effect of the shape of the device on the electric field distribution has been examined using device simulation. Simulations show circular shape devices provide a more uniform electric field distribution at the junction compared to that of rectangular and octagonal devices. We fabricated PGSPAD devices in a sub-micron process (0.5 μm CMOS process and 0.5 μm high voltage CMOS process) and a deep-submicron process (180 nm CMOS process). Experimental results show that the breakdown voltage increases with gate voltage. The breakdown voltage increases by approximately 1.5 V and 2.5 V with increasing applied gate voltage magnitude from 0 V to 6 V for devices fabricated in 0.5 μm and 180 nm standard CMOS process respectively.

A Digitally Controlled Oscillator for ADPLL Application

In order to solve the defects in performance for analog RF circuit in deep submicron process, this paper discusses a new type of LC oscillators(Digitally Controlled Oscillator), which uses digital RF method to achieve the technology requirements of wireless communication. This new type of oscillator uses MOS varactor arrays to moderating the output frequency, through the using of digitally Sigma-Delta technology, we can get more precise resolution , and through using three modes progressively working way can make this kind of structure easily implement in process.

A 800μW 1GHz Charge Pump Based Phase-Locked Loop in Submicron CMOS Process

A 800μW 1GHz Charge Pump Based Phase-Locked Loop in Submicron CMOS ProcessDemand of modern measurement systems in submicron CMOS process introduced new challenges in design of low power high frequency clock generation systems. Technical possibilities for clock generation using classical oscillator based on a quartz filter is limited to tens of megahertz. Thus, 1 GHz clock generation is not possible without a frequency multiplier system. It is difficult to achieve, because in submicron process, where the integration of analog and digital blocks poses serious challenges. The proposed solution is a low power charge pump phase-locked loop (CPPLL) with the center frequency of 1 GHz. It combines various modern circuit techniques, whose main aim is to lower power consumption, which is below 800 μW for the whole PLL, while maintaining good noise properties, where the jitter rms is 8.87 ps. The proposed phase-locked loop is designed in 0.18 μm CMOS process.