DS1602
Elapsed Time Counter
www.maxim-ic.com
www.maxim-ic.com
FEATURES
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Two 32-bit counters keep track of real-time
and elapsed time
Counters keep track of seconds for over 125
years
Battery powered counter counts seconds from
the time battery is attached until VBAT is less
than 2.5V
VCC powered counter counts seconds while
VCC is above VTP and retains the count in the
absence of VCC under battery backup power
Clear function resets selected counter to 0
Read/write serial port affords low pin count
Maximum current drain of less than 1 µA
from VBAT pin when serial port is disabled
One byte protocol defines read/write, counter
address and software clear function
8-pin DIP or optional 8-pin SOIC
Operating temperature range of -40°C to
+85°C
Reduced performance operation down to
VCC = 2.5V
Underwriters Laboratory (UL) recognized
PIN ASSIGNMENT
RST
1
8
VCC
DQ
2
7
X1
CLK
3
X2
GND
4
6
5
VBAT
DS1602
8-Pin DIP (300mil)
RST
1
8
VCC
DQ
2
7
X1
CLK
3
6
X2
GND
4
5
VBAT
DS1602
8-Pin SOIC (208mil)
Package Dimension Information
www.maxim-ic.com/TechSupport/DallasPackInfo.htm
PIN DESCRIPTION
RST
CLK
DQ
GND
X1, X2
VBAT
VCC
- Reset
- Clock
- Data Input/Output
- Ground
- Crystal Inputs
- + Battery Input
- +5V
DESCRIPTION
The DS1602 is a real-time clock/elapsed time counter designed to count seconds when V power is
CC
applied and continually count seconds under battery backup power with an additional counter regardless
of the condition of VCC. The continuous counter can be used to derive time of day, week, month, and year
by using a software algorithm. The V powered counter will automatically record the amount of time
CC
that V power is applied. This function is particularly useful in determining the operational time of
CC
equipment in which the DS1602 is used. Alternatively, this counter can also be used under software
control to record real-time eve nts. Communication to and from the DS1602 takes place via a 3-wire serial
port. A 1-byte protocol selects read/ write functions, counter clear functions and oscillator trim. A low
cost 32.768kHz crystal attaches directly to the X1 and X2 pins. If battery powered-only operation is
desired, the VBAT pin must be grounded and the VCC pin must be connected to the battery.
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata.
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