PCA8565-Real Time Clock
Created: Sep 12, 2014
No description available.
This project uses NXP PCA8565 that performs timekeeping, alarm and operation as well as “failsafe” functions such as recovery from power failure. It keeps track of the accurate time even when the system is turned OFF. It includes an on-chip voltage detector that will automatically set the bit VL if one of the following four conditions occur: the power has just been applied, the power has dipped down and then recovered, the power has gone away and then come back again, or when the oscillator stops running.
The PCA8565 is a CMOS1 real time clock and calendar optimized for low power consumption. A programmable clock output, interrupt output and voltage-low detector are also provided. All address and data are transferred serially via a two-line bidirectional I2C-bus with a maximum bus speed of 400kbps. The built-in word address register is incremented automatically after each written or read data byte. It provides a year, month, day, weekday, hours, minutes and seconds based on a 32.768kHz quartz crystal. It features alarm and timer functions, low current, and extended operating temperature range of -40 degrees Celsius to +125 degrees Celsius. It further contains an 8-bit year register that can hold values from 00 to 99 in BCD format, which also compensates for leap years, thus leap year correction is automatic.
The PCA8565TS Real Time Clock has a primary benefit of low power consumption. It can continue to keep time while the primary source of power is OFF or unavailable since it can run on alternate power. Its application will be manifested in data logging where the system could be placed in a low power “sleep mode” when idle and an alarm could be used to “wake up” the system at the appropriate time to collect data. It can also be used in time stamping where fax machines can still stamp the time when a document was sent and received after a system power failure. Also, it can be used as a service reminder for test equipment such as oil change, engine tune-up automobile and calibration even on sudden power failure.