DS1302
Trickle Charge Timekeeping Chip
www.dalsemi.com
FEATURES
Real time clock counts seconds, minutes
hours, date of the month, month, day of the
week, and year with leap year compensation
valid up to 2100
31 x 8 RAM for scratchpad data storage
Serial I/O for minimum pin count
2.0鈥?.5V full operation
Uses less than 300 nA at 2.0V
Single鈥揵yte or multiple鈥揵yte (burst mode)
data transfer for read or write of clock or
RAM data
8鈥損in DIP or optional 8鈥損in SOICs for
surface mount
Simple 3鈥搘ire interface
TTL鈥揷ompatible (V
CC
= 5V)
Optional industrial temperature range
鈥?0掳C to +85掳C
DS1202 compatible
Recognized by Underwriters Laboratory
PIN ASSIGNMENT
V
CC2
X1
X2
GND
1
2
3
4
8
7
6
5
V
CC1
SCLK
I/O
RST
DS1302
8-Pin DIP (300 mil)
V
CC2
X1
X2
GND
1
2
3
4
8
7
6
5
V
CC1
SCLK
I/O
RST
DS1302S 8-Pin SOIC (200 mil)
DS1302Z 8-Pin SOIC (150 mil)
V
CC2
NC
X1
NC
X2
NC
NC
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
CC1
NC
SCLK
NC
I/O
NC
NC
RST
ORDERING INFORMATION
PART #
DS1302
DS1302N
DS1302S
DS1302SN
DS1302Z
DS1302ZN
DS1302S-16
DS1302SN-16
DESCRIPTION
8鈥揚in DIP
8-Pin DIP (Industrial)
8鈥揚in SOIC (200 mil)
8鈥揚in SOIC (Industrial)
8鈥揚in SOIC (150 mil)
8鈥揚in SOIC (Industrial)
16-Pin SOIC (300 mil)
16-Pin SOIC (Industrial)
16-Pin SOIC
PIN DESCRIPTION
X1, X2
GND
RST
I/O
SCLK
V
CC1
, V
CC2
鈥?32.768 kHz Crystal Pins
鈥?Ground
鈥?Reset
鈥?Data Input/Output
鈥?Serial Clock
鈥?Power Supply Pins
DESCRIPTION
The DS1302 Trickle Charge Timekeeping Chip contains a real time clock/calendar and 31 bytes of static
RAM. It communicates with a microprocessor via a simple serial interface. The real time clock/calendar
provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is
automatically adjusted for months with less than 31 days, including corrections for leap year. The clock
operates in either the 24鈥揾our or 12鈥揾our format with an AM/PM indicator.
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