RTC - Clock-Calendar
2.7/3.6V - SPI - SOIC 28
                                RTC/Bateria - Cronómetro-Calendar
5V - 16Kbit - DIL24
                                RTC - Cronómetro-Calendar
5V - 256Kbit - DIL28
                                Bateria/Cristal for RTC
 
                                Low-power single CMOS timer - SOIC 8