Real-Time Clock
Typical Operating Characteristics
(V
CC
= +5.0V, T
A
= +25°C, unless otherwise noted.)
DS12885/DS12887/DS12887A/DS12C887/DS12C887A
I
BAT1
vs. V
BAT
vs. TEMPERATURE
DS12885 toc01
OSCILLATOR FREQUENCY
vs. V
CC
32768.70
32768.60
FREQUENCY (Hz)
32768.50
32768.40
32768.30
32768.20
32768.10
DS12885 toc02
V
CC
= 0V
300
+85°C
+25°C
I
BAT
(nA)
250
0°C
+70°C
200
+40°C
-40°C
150
2.5
2.8
3.0
3.5
3.3
V
BAT
(V)
3.8
4.0
32768.00
4.5
4.8
5.0
V
CC
(V)
5.3
5.5
Functional Diagram
X1
OSC
X2
V
CC
GND
POWER
CONTROL
DIVIDE
BY 8
DIVIDE
BY 64
DIVIDE
BY 64
16:1 MUX
SQUARE-
WAVE
GENERATOR
SQW
IRQ
V
BAT
DS12885
CS
R/W
DS
AS
MOT
RESET
AD0–AD7
BUS
INTERFACE
CLOCK/CALENDAR
UPDATE LOGIC
IRQ
GENERATOR
REGISTERS A, B, C, D
CLOCK/CALENDAR AND
ALARM REGISTERS
BUFFERED CLOCK/
CALENDAR AND ALARM
REGISTERS
USER RAM
114 BYTES
RLCR
_____________________________________________________________________
7
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
