DS1602
Elapsed Time Counter
www.dalsemi.com
FEATURES
§
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 V
BAT
is less
than 2.5 volts
§
V
CC
powered counter counts seconds while
V
CC
is above 4.25 volts and retains the count
in the absence of V
CC
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 V
BAT
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 V
CC
= 2.5V
PIN ASSIGNMENT
RST
DQ
CLK
GND
1
2
3
4
8
7
6
5
V
CC
X1
X2
V
BAT
DS1602
8-Pin DIP (300-mil)
RST
DQ
CLK
GND
1
2
3
4
8
7
6
5
V
CC
X1
X2
V
BAT
DS1602
8-Pin SOIC (200-mil)
PIN DESCRIPTION
RST
CLK
DQ
GND
X1, X2
V
BAT
V
CC
- Reset
- Clock
- Data Input/Output
- Ground
- Crystal Inputs
- + Battery Input
- +5 Volts
DESCRIPTION
The DS1602 is a real time clock/elapsed time counter designed to count seconds when V
CC
power is
applied and continually count seconds under battery backup power with an additional counter regardless
of the condition of V
CC
. The continuous counter can be used to derive time of day, week, month, and year
by using a software algorithm. The V
CC
powered counter will automatically record the amount of time
that V
CC
power is applied. This function is particularly useful in determining the operational time of
equipment in which the DS1602 is used. Alternatively, this counter can also be used under software
control to record real time events. 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 32.768 kHz crystal attaches directly to the X1 and X2 pins. If battery powered-only operation is
desired, the V
BAT
pin must be grounded and the V
CC
pin must be connected to the battery.
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070199
DALLAS [ DALLAS SEMICONDUCTOR ]
