The detection of charged particles in subatomic physics experiment is a real challenge for today's microelectronics sensors. These experiments need highly granular, thin, radiation tolerant, fast and multilayer silicon detectors installed very close to the interaction region to detect the charged particles.CMOS monolithic active pixel sensors(MAPS) are charged particle tracking devices, integrating on the same substrate radiation sensitive detector elements with their front-end readout electronics.

SUN Quan of Institute of Acoustics, Chinese Academy of Sciences carried out a series of studies and presented a high-performance CMOS charge pump supply-noise-insensitive phase-locked loop (SNI-PLL) for on-chip clock generation of Monolithic Active Pixel Sensors (MAPS).

The SNI-PLL employs a voltage regulator which provides two stable power supplies to the charge pump and the voltage-controlled oscillator (VCO), respectively.The voltage regulator achieves a Power Supply Noise Rejection (PSNR) of -40 dB over the entire frequency spectrum by using virtual grounded cascode compensation technique. The SNI-PLL generates a 160 MHz clock with a Time Interval Error (TIE) of 0.062 UI (Unit Interval) from a 10 MHz reference clock in a noisy power supply environment.

This research result was published on the recently issued IEEE Sensors Journal(2011,11(10):2212-2219).