ST unveils ‘world’s smallest’ real time clock and crystal

According to ST, it 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 semiconductor specialist says this delivers the world's smallest integrated rtc/crystal, measuring 3.2 x 1.5mm and offering 'ultra low' power consumption. The M41T62 is designed for battery powered designs and by operating at low voltages from 1.3 to 4.4V, it can be driven directly from a Li-ion battery, drawing only 350nA. Many integrated microcontrollers have an on chip rtv, but these often provide limited features and an external crystal is always required. Unlike designing with microcontrollers, or discrete solutions, ST claims this integrated solution takes care of the required and sometimes troublesome matching of the crystal and the rtc. "This state of the art real time clock, embedded in this small volume crystal package, provides the perfect solution for any portable design," said Francesco Italia, director of the sensors and microactuators business unit within ST's MEMS, Sensors and High Performance Analog Division. "It saves space, optimises power consumption, and can run directly from a rechargeable Lithium-Ion battery. This turn key solution alleviates the headache for designers of matching the right crystal with the right real time clock silicon." The device produces a stable 32kHz signal on start up, as well as oscillator failure detection, 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. It is also UL certified and has a built in reverse diode.