DS1307
64 x 8, Serial, I
2
C Real-Time Clock
GENERAL DESCRIPTION
The DS1307 serial real-time clock (RTC) is a low-
power, full binary-coded decimal (BCD) clock/calendar
plus 56 bytes of NV SRAM. Address and data are
transferred serially through an I
2
C, bidirectional bus.
The clock/calendar provides seconds, minutes, hours,
day, date, month, and year information. The end of
the month date is automatically adjusted for months
with fewer than 31 days, including corrections for leap
year. The clock operates in either the 24-hour or 12-
hour format with AM/PM indicator. The DS1307 has a
built-in power-sense circuit that detects power failures
and automatically switches to the backup supply.
Timekeeping operation continues while the part
operates from the backup supply.
FEATURES
Real-Time Clock (RTC) Counts Seconds,
Minutes, Hours, Date of the Month, Month, Day of
the week, and Year with Leap-Year
Compensation Valid Up to 2100
56-Byte, Battery-Backed, General-Purpose RAM
with Unlimited Writes
I
2
C Serial Interface
Programmable Square-Wave Output Signal
Automatic Power-Fail Detect and Switch Circuitry
Consumes Less than 500nA in Battery-Backup
Mode with Oscillator Running
Optional Industrial Temperature Range:
-40°C to +85°C
Available in 8-Pin Plastic DIP or SO
Underwriters Laboratories (UL) Recognized
TYPICAL OPERATING CIRCUIT
V
CC
CRYSTAL
V
CC
V
CC
R
PU
R
PU
PIN CONFIGURATIONS
TOP VIEW
X1
X2
V
BAT
GND
SO (150 mils)
V
CC
SQW/OUT
SCL
SDA
X1
X2
V
BAT
GND
V
CC
SQW/OUT
SCL
SDA
X1 X2
SCL
CPU
SDA
V
CC
SQW/OUT
DS130
V
BAT
GND
R
PU
= t
r
/C
b
PDIP (300 mils)
ORDERING INFORMATION
PART
DS1307+
DS1307N+
DS1307Z+
DS1307ZN+
DS1307Z+T&R
DS1307ZN+T&R
TEMP RANGE
0°C to +70°C
-40°C to +85°C
0°C to +70°C
-40°C to +85°C
0°C to +70°C
-40°C to +85°C
VOLTAGE (V)
5.0
5.0
5.0
5.0
5.0
5.0
PIN-PACKAGE
8 PDIP (300 mils)
8 PDIP (300 mils)
8 SO (150 mils)
8 SO (150 mils)
8 SO (150 mils) Tape and Reel
8 SO (150 mils) Tape and Reel
TOP MARK*
DS1307
DS1307N
DS1307
DS1307N
DS1307
DS1307N
+Denotes
a lead-free/RoHS-compliant package.
*A
“+” anywhere on the top mark indicates a lead-free package. An “N” anywhere on the top mark indicates an industrial temperature range
device.
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REV: 100208
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
