A Versatile Timing Microsystem Based on Wafer-Level Packaged XTAL/BAW Resonators With Sub- \mu W RTC Mode and Programmable HF Clocks

• Published in: IEEE journal of solid-state circuits Vol. 49; no. 1; pp. 212 - 222
• Main Authors: Ruffieux, David, Scolari, Nicola, Giroud, Frederic, Thanh-Chau Le, Dalla Piazza, Silvio, Staub, Felix, Zoschke, Kai, Manier, Charles-Alix, Oppermann, Hermann, Suni, Tommi, Dekker, James, Allegato, Giorgio
• Format: Journal Article
• Language: English
• Published: IEEE 01.01.2014
• Subjects: Clocks; Gold; Hybrid integration; MEMS; oscillator; Oscillators; Packaging; programmable clocks; real-time clock (RTC); Silicon; temperature sensor; Temperature sensors; Timing; wafer level packaging
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/JSSC.2013.2282111

This paper introduces and demonstrates with high yield a novel concept for the packaging under vacuum of tuning fork quartz XTALs on top of a silicon interposer equipped with TSVs. It paves the way to the implementation of a monolithic timing microsystem where the ASIC is part of the housing of a newly designed tiny 131-kHz XTAL to reach extreme module miniaturization (1.5 × 1.1 × 0.7 mm 3 ) and integrity. As this task is still ongoing, an early demonstration of the generic versatile timing module is presented using a chip-on-board approach with standalone conventionally packaged XTAL and BAW resonators. The module achieves 0.4 μW power dissipation and ±2 ppm stability over -40 °C to 85 °C in RTC mode and can deliver on-demand programmable clocks between 1-50 MHz. The latter are obtained either with a RC PLL or after division of the signal obtained from a 2-GHz BAW DCO at a power dissipation of 100 μW and 5.3 mW, respectively.