Murata touts smallest MEMS resonator for wearables

By Alex Pluemer, contributing writer

Murata Manufacturing Co., Ltd. recently unveiled what it claims is the smallest 32.768-kHz microelectromechanical (MEMS) resonator on the market. Murata believes that the new MEMS resonator will be a smaller, more power-efficient solution for IoT, wearable, and health-care devices.

Like other 32.768-kHz resonators, Murata’s new design keeps accurate time while keeping resources not currently in operation in deep-sleep mode, therefore reducing power consumption and maximizing battery charge. The implementation of MEMS technology allows the new resonator to deliver high-quality frequency accuracy and a low equivalent series resistance (ESR) while reducing power consumption, all in a package that is more than 50% smaller than its nearest competitors.

Key features of the new 32.768-kHz MEMS resonator include:

• Compact design: At 0.9 × 0.6 × 0.3 mm, Murata’s design is over 50% smaller than typical tuning fork quartz-crystal resonators.
• Power-efficient: The MEMS resonator is capable of providing a stable reference clock signal while using 13% less power than more traditional quartz-crystal resonators due to its low (75-kΩ) ESR, based on internal testing.
• IC-compatible: The resonator’s silicon-based wafer-level chip-scale packaging allows it to be co-packaged with an integrated circuit, thereby doing away with the necessity of any external low-frequency clock references.
• Integrated load capacitors: Eliminates the need for external multilayer ceramic load capacitors and further reduces size, creating more circuit design space and flexibility.

The resonator provides frequency temperature characteristics of less than 160 ppm (at an operating temperature range of −30°C to 85°C) with an initial frequency accuracy (25°C) that is on par with or better than most conventional tuning fork quartz-crystal resonators.

Murata is scheduled to begin mass production of the new WMRAG series MEMS resonator in December 2018.