EPSON, represented by TE Australia, has developed an ultra-compact and thin real time clock (RTC) module called the RX-4591CF.
The RX-4591CF forms a family of RTCs, which are claimed to be one of the world's smallest serial interface module real time clock including a 32,768kHz crystal available on the market.
The distinguishing feature of this RTC is that it combines the real-time-clock IC with the needed 32,768 kHz clock crystal in one compact ceramic housing.
Not only does this lead to a reduction of space on the PCB, but also Epson optimises the RTC for power consumption, performance and reliability.
This way the RTC is well suited for battery powered applications. For example: mobile equipment (requiring a clock function), digital still cameras, digital video cameras, PDAs and other small mobile information equipment.
At the heart of the RX-4591CF is the ultra-compact 32,768 kHz tuning-fork crystal FC-135. Control of the serial interface can be done using either 4 lines, or using 3 lines while connecting data I/O pins together.
In addition to an alarm and timer function, the module features a 32,768 kHz output (Fout). With an output-enable option, the Fout signal could be used to drive additional ICs.
The RTC can be operated with 1.6V to 5.5V, and the typical power consumption for 3V is 300nA.
The compact ceramic SMD package measuring 5.0 x 3.2 x 1.2mm in size, makes the RX-4591CF suitable for applications with limited space.