CBM1307
OPERATION INSTRUCTION
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Features
Count of seconds, minutes, hours, week days, date, months and years with consideration of
the leap years (before 2100);
56 bytes of the power self-sufficient RAM for the data storage;
Two-wire consecutive interface;
Programmable rectangular output signal;
Automatic determination of the supply voltage drop and the switching diagram;
Consumption of less than 500nА in the back-up supply mode with the operating generator;
Temperature range of the industrial application: -40℃ – +85℃
Accuracy is better than ±1 minute per month
General Description
CBM1307 is essentially the binary – decimal digital watch with a calendar, it has the additional 56
bytes of the power self-sufficient static RAM and possesses the low power consumption. The
addresses and data are applied consecutively via the two-wire bi-directional bus. The
microcircuit is intended for count of the real time in hours, minutes and seconds, count of week
days, date, month and year. The last day of the month is automatically adjusted for the months of
less, than 31 days, including correction for the leap year. The watches function in the 24-hour
format or in the 12-hour format with the AM / PM-indicator. CBM1307 has the built-in power
supply control circuit, which determines the supply disruption and automatically switches over
the device into the battery mode.
CBM1307
OPERATION INSTRUCTION
www.corebai.com
FOCUS ON DEVELOPMENT • SINCERELY SERVICE • INNOVATIVE FUTURE
CATALOG
Features....................................................................................................................................................
General Description.................................................................................................................................
Pin Configuration.................................................................................................................................. 1
Pin Assignment......................................................................................................................................1
Block Diagram.......................................................................................................................................2
Operating Temperatures Range............................................................................................................. 2
Dc Electrical Characteristics..................................................................................................................3
Ac Electrical Characteristics..................................................................................................................4
Typical Operation Characteristics......................................................................................................... 5
Timing Chart..........................................................................................................................................6
Functioning............................................................................................................................................6
Addresses Chart Of Rtc And Ram.........................................................................................................6
Oscillator Circuit................................................................................................................................... 7
Crystal Specifications*..........................................................................................................................7
Clock Accuracy..................................................................................................................................... 7
Oscillator Circuit Showing Internal Bias Network............................................................................... 7
Recommended Layout For Crystal........................................................................................................8
Hours And Calendar.............................................................................................................................. 8
Registers RTC CBM1307......................................................................................................................9
Control Register.................................................................................................................................... 9
Two-Wire Serial Data Bus...................................................................................................................10
Data Transfer By The Serial Two-Wire Bus........................................................................................11
CBM1307 Can Operate In The Two Following Modes...................................................................... 12
Application Note..................................................................................................................................14
Typical Application Circuit................................................................................................................. 24
Package Dimension............................................................................................................................. 25
Package/Ordering Information............................................................................................................26
1. Test fixture overview................................................................................................................27
2. Real Time Clock Program........................................................................................................29
3. Example Source for RTC....................................................................................................... ..35
4. Test Procedure for RTC............................................................................................................39