PCF8573T

The PCF8573T is type of clock/calendar with power fail detector.The PCF8573T is a low threshold, CMOS circuit that works as a real time clock/calendar. It transfers the addresses and data serially via the two-line bidirectional I2C-bus.The IC incorporates an addressable time counter and an addressable alarm register for minutes, hours, days and months. Three special control/status flags, COMP, POWF and NODA, are also available. Back-up for the clock dur ing supply interruptions is offered by a 1.2 V nickel cadmium battery. The time base of PCF8573T is generated from a 32.768 kHz crystal-controlled oscillator.

Features of the PCF8573T are:(1)serial input/output IC-bus interface for minutes, hours,days and months;(2)additi onal pulse outputs for seconds and minutes;(3)alarm register for presetting a time for alarm or remote switching functions;(4)on-chip power fail detector;(5)separate ground pin for the clock allows easy implementation of battery back-up during supply interruption;(6)crystal oscillator control (32.768 kHz);(7) low power consumption.

The limiting values of the PCF8573T can be summarized as:(1):supply voltage (pin 16 to pin 15) is-0.3V min and +8.0 V max;(2):supply voltage (pin 16 to pin 8) is -0.3V min and+8.0 V max;(3):input voltage:pins 4 and 5 (with input imp edance of minimum 500 ) is VSS2 - 0.8 V min and VDD + 0.8 V max;pins 6, 7, 13 and 14 is VSS1 - 0.6 V min and VDD + 0.6 V max;any other pin is VSS2 - 0.6V min and VDD + 0.6 V max(4): DC input current is 10 mA max;(5):DC output current is 10 mA max;(6):total power dissipation per package is 200 mW max;(7):power dissipation per output is 100 mW max;(8):operating ambient temperature ranges from-40°C +85 °C;(9):storage temperature ranges from -55°C +125 °C.etc.