The 32.768-kHz MEMS resonator is more than 50% smaller than typical tuning fork quartz crystal resonators

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 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 32.768kHz MEMS resonator include:

  • Compact design: At 0.9 x 0.6 x 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 and 85°C) with an initial frequency accuracy (25°C) that is on par with or better than most conventional
quartz tuning fork crystal resonators.

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