DS1307+ Maxim Integrated Products, DS1307+ Datasheet - Page 6

• Manufacturer Part Number: DS1307+
• Description: IC RTC SERIAL 512K 8-DIP
• Manufacturer: Maxim Integrated Products
• Type: Clock/Calendar/NVSRAMr

Specifications of DS1307+

• Memory Size: 56B
• Time Format: HH:MM:SS (12/24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Function: Clock/Calendar
• Rtc Memory Size: 56 Byte
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: Through Hole
• Rtc Bus Interface: Serial (I2C)
• Supply Current: 1.5 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIN DESCRIPTION
DETAILED DESCRIPTION
The DS1307 is a low-power clock/calendar with 56 bytes of battery-backed SRAM. The clock/calendar provides
seconds, minutes, hours, day, date, month, and year information. The date at the end of the month is automatically
adjusted for months with fewer than 31 days, including corrections for leap year. The DS1307 operates as a slave
device on the I
code followed by a register address. Subsequent registers can be accessed sequentially until a STOP condition is
executed. When V
address counter. Inputs to the device will not be recognized at this time to prevent erroneous data from being
written to the device from an out-of-tolerance system. When V
current battery-backup mode. Upon power-up, the device switches from battery to V
V
main elements of the serial RTC.
BAT
PIN
1
2
3
4
5
6
7
8
+0.2V and recognizes inputs when V
SQW/OUT
NAME
GND
SDA
V
SCL
V
2
X1
X2
BAT
C bus. Access is obtained by implementing a START condition and providing a device identification
CC
CC
falls below 1.25 x V
Connections for Standard 32.768kHz Quartz Crystal. The internal oscillator circuitry is
designed for operation with a crystal having a specified load capacitance (C
X1 is the input to the oscillator and can optionally be connected to an external 32.768kHz
oscillator. The output of the internal oscillator, X2, is floated if an external oscillator is
connected to X1.
Backup Supply Input for Any Standard 3V Lithium Cell or Other Energy Source. Battery
voltage must be held between the minimum and maximum limits for proper operation.
Diodes in series between the battery and the V
backup supply is not required, V
(V
circuitry as 1.25 x V
DS1307 for more than 10 years in the absence of power at +25°C.
Note: For more information on crystal selection and crystal layout considerations, refer to
Application Note 58: Crystal Considerations with Dallas Real-Time Clocks.
UL recognized to ensure against reverse charging current when used with a lithium
battery. Go to: www.maxim-ic.com/qa/info/ul/.
Ground
Serial Data Input/Output. SDA is the data input/output for the I
SDA pin is open drain and requires an external pullup resistor. The pullup voltage can be
up to 5.5V regardless of the voltage on V
Serial Clock Input. SCL is the clock input for the I
data movement on the serial interface. The pullup voltage can be up to 5.5V regardless of
the voltage on V
Square Wave/Output Driver. When enabled, the SQWE bit set to 1, the SQW/OUT pin
outputs one of four square-wave frequencies (1Hz, 4kHz, 8kHz, 32kHz). The SQW/OUT
pin is open drain and requires an external pullup resistor. SQW/OUT operates with either
V
V
Primary Power Supply. When voltage is applied within normal limits, the device is fully
accessible and data can be written and read. When a backup supply is connected to the
device and V
function continues unaffected by the lower input voltage.
CC
CC
PF
. If not used, this pin can be left floating.
) voltage at which access to the RTC and user RAM is denied is set by the internal
or V
BAT
applied. The pullup voltage can be up to 5.5V regardless of the voltage on
CC
is below V
CC
BAT
CC
.
BAT
, the device terminates an access in progress and resets the device
is greater than 1.25 x V
nominal. A lithium battery with 48mAh or greater will back up the
TP
, read and writes are inhibited. However, the timekeeping
6 of 14
BAT
must be grounded. The nominal power-fail trip point
CC
FUNCTION
CC
falls below V
.
BAT
DS1307 64 x 8, Serial, I
BAT
. The block diagram in Figure 1 shows the
2
C interface and is used to synchronize
pin may prevent proper operation. If a
BAT
, the device switches into a low-
CC
2
C serial interface. The
when V
2
C Real-Time Clock
CC
L
is greater than
) of 12.5pF.