PORTLAND, Ore. A real-time clock oscillator unveiled by Epson Toyocom Corp. is said to require 70 percent less board space while occupying 75 percent less volume that its predecessor.
The new real-time oscillator (SG-3050BC) uses Epson's proprietary QMEMS process to squeeze all functions into a 2.2- by 1.4- by 1-mm package.
The 32.768-KHz crystal oscillator is claimed to be the smallest currently available, according to Bob Porooshani, general manager at Epson Electronics America, Inc. (El Segundo, Calif.) "Our customers will use it to provide the timing signals for clocks, microcontroller subclocks and timer function in a variety of space-constrained applications."
The ultra-small package was achieved by combining a crystal in a ceramic package sealed together with its phased-locked loop (PLL) circuitry in a molded plastic housing. The configuration saved board space compared to applications using separate crystals and PLLs.
The unit's frequency is calibrated at the factory prior to shipment, and is aimed at clock applications in portable consumer products such as cellphones and digital still cameras, industrial instruments and machine tools as well as for automotive navigation systems, GPS modules and engine control units.
Epson previously claimed the world's smallest real-time clock chip, combining oscillator functions with an ASIC containing the logic circuitry for maintaining timing functions.
Epson said its QMEMS process uses the same photolithography, etching, metallization and sacrificial-layer removal steps as silicon MEMS chips. The company claims silicon MEMS requires more signal conditioning to rival the performance of the QMEMS. The reason is that quartz is a piezoelectric material that naturally oscillates at a steady rate when activated with an electric current.