SD3031 http://www.whwave.com.cn
REAL -TIME CLOCK IC
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SD3031
1.General Description
The SD3031 is a CMOS type real-time clock with a built-in crystal and an integrated
temperature-compensated crystal oscillator (TCXO),which is connected to the CPU via
2-wires and capable of serial transmission of clock and calendar data to the CPU.
The SD3031 has dual power supply system. When the primary power supply goes
down to an assigned value or resumes from low power, the system can switch between
the primary power supply and battery automatically.
The SD3031 can generates various periodic interrupt clock pulses lasting for long
period, and three alarm interrupts can be made by year,month,date,days of the week,
hours, and minutes.,seconds. It also provides a selectable 4096Hz~1/16Hz clock output
for an external MCU. The product incorporates a time trimming circuit that adjusts the
clock with higher precision by adjusting any errors in crystal oscillator frequencies . A
70-bytes general SRAM is implemented in the SD3031.
2.Features：
Operation voltage range:2.7V~5.5V.
Low power consumption: typical 0.8uA at 3.0V.
Fast (400kHz) I
2
C Interface.
High frequency accuracy:±3.8ppm at 25℃.
Real-Time Clock Counts Seconds, Minutes,Hours, Day, Date, Month, and Year
with Leap Year Compensation Valid Up to 2100.
Time-of-Year,Month,Day,Week,Hour,Minute,Second Alarms.
Programmable Square-Wave Output:4096hz...1hz..1/16hz.
24-bit countdown timer, optional 4 clock sources (4096HZ, 64HZ, 1HZ, 1min)
High precision temperature compensated circuit.
12-houe/24-hour time display selectable.
70 bytes general SRAM implemented for system data backup.
8 Bytes ID code
CMOS logic
ROHS Recognized.
Package: SOP8(208mil)
SD3031 http://www.whwave.com.cn
3.Pin Configuration
NAME
FUNCTION
SCL
Serial Clock Input. This pin is the clock input for the I
2
C serial interface and is used to
synchronize data movement on the serial interface. Up to 5.5V can be used for this
pin, regardless of the voltage on VCC.
SDA
Serial Data Input/Output. This pin is the data input/output for the I
2
C serial interface.
This open-drain pin requires an external pullup resistor. The pullup voltage can be up
to 5.5V, regardless of the voltage on VCC.
INT
Active-Low Interrupt or Square-Wave Output. This open-drain pin requires an external
pullup resistor connected to a supply at 5.5V or less. If not used, this pin can be left
floating.
VBAT
External Battery input pin.
VCC
DC Power Pin for Primary Power Supply. This pin should be decoupled using a 0.1μF
to 1.0μF capacitor.
NC
No Conncected
GND
Ground