专家园地

For the first time, PCIe allows Refclk jitter compliance to be measured using a phase noise analyzer. Learn about the latest PCIe BASE Rev. 5.0 specs for determining Refclk jitter compliance, about the pros/cons of phase noise vs oscilloscope methods, how phase noise aliases in sampled systems, and algorithm development. This topic was presented at DesignCon in 2019. (Presentation Slides)

This paper describes a novel DualMEMS™ architecture, how it differs in construction and fabrication compared to quartz-based devices, and how thermal coupling affects oscillator performance in response to thermal disturbances (frequency slope). Thermal simulations showing temperature offsets are presented.

This paper presents a dual-MEMS resonator-based temperature sensor with 20-μK resolution and conversion rate of 200 S/s, and FOM of 0.04 pJK2. The implementation of a MEMS resonator design with two functional modes and associated circuitry are discussed. This paper appeared in the IEEE Journal of Solid-State Circuits in 2017.

Precision MEMS oscillators require a TDC that adjusts the multiplication factor of a frac-N PLL to compensate for frequency variation over temperature. This paper presents a TDC based on dual-MEMS resonators with 40 μK resolution and FOM of 0.12pJK2 that has little impact on phase noise. This paper was presented at ISSCC in 2016. (Presentation Slides)

This paper describes the system-level and circuit-level design of the first production 32-kHz low-power MEMS-based oscillator (±100 ppm) and TCXO (±3 ppm) with a small form-factor for timekeeping and low power functions in space-constrained mobile devices. This paper appeared in the IEEE Journal of Solid-State Circuits in 2015.

Today’s 32 kHz quartz resonators and oscillators are facing challenges in size reduction. This paper introduces a 32 kHz MEMS-based oscillator suited for mobile time-keeping applications that require small form-factor, tight frequency stability, and micro-power 32.768 kHz clock references. This paper was presented at ISSCC in 2014. (Presentation Slides)

This paper introduces the first commercial MEMS TCXO that delivers <1 ppm frequency stability from -40 to +85°C. Its system architecture, MEMS resonator, and key circuit blocks are described along with accompanying benefits, such as programmability and improved reliability and robustness. This paper was presented at AACD in 2013.

Programmable oscillators offer flexibility for clock tree optimization and spread-spectrum modulation for EMI reduction in FPGA-based applications. This paper introduces a timing architecture that helps designers improve system performance and solve clocking issues. This paper was presented at ESC in 2012. (Presentation Slides)

For low bandwidth PLLs, high-Q controlled oscillators offer low gain and high stability. This paper examines system flexibility and robustness along with the impact of quantization, update delay and loop performance for: 1) varactor-based VCXOs, 2) PLL-based VCXOs, and 3) digitally-controlled oscillators. This paper was presented at ESC in 2012. (Presentation Slides)

In SyncE and PTP applications, local oscillators must deliver a stable reference regardless of environmental factors. This paper describes the performance requirements and characteristics of various TCXOs used in telecom systems and presents measurement results for ADEV, TDEV (wander), and MTIE under airflow and temp transients.