As miniaturization continues to be a key goal for designers of high-tech products STMicroelectronics has announced the world's smallest combined crystal and real-time clock (RTC) IC for time, calendar and alarm functions. ST has combined the world's smallest real-time clock die and a matched oscillator crystal in the same package size as the smallest crystal-only devices on the market today; the integrated RTC/crystal measures 3.2 x 1.5mm and offers very low power consumption.
The is well-suited to the needs of battery-powered designs. By operating at low voltages from 1.3V to 4.4V, it can be driven directly from a Li-ion battery and draws only 350nA. Many integrated microcontrollers have an on-chip RTC, but these often provide limited features and an external crystal is always required. Unlike designing with microcontrollers, or discrete solutions, this integrated solution takes care of the required and sometimes troublesome matching of the crystal and the RTC.
The produces a stable 32kHz signal on start-up, which ensures reliable starting from many of today's processors and subsystems such as Bluetooth modules. Additional features enhancing design and system performance include oscillator failure detection (OFD), which helps the system detect power faults. Actions such as power-down time stamping, low-battery detection can be done without the additional external components needed by a microcontroller RTC. The device is also UL certified and has a built-in reverse diode.
The improves the performance of systems whose functions rely on data logging, time stamping, interval monitoring or synchronization. These can be found in SLR digital cameras, GPS receivers, portable multimedia players, card readers, portable medical monitors such as glucose meters.
The is entering into volume production now in the LCC8 leadless package, priced at approximately $1.50 in quantities of 1000 units.