Real Time Clock Modules - Seiko Epson
RTC-72421/72423
Features
鈥?Built-in quartz crystal makes regulation unnecessary
and allows for easy design
鈥?ALE INPUT terminal available for 8048, 8051 and
8085 series
鈥?Incorporates built-in time counters (year, month,
week, day)
鈥?12hr/24hr clock switchcover function and automatic
leap year setting
鈥?30 seconds error adjustment function
鈥?READ, WRITE, HOLD, STOP, RESET and CHIP SELECT
inputs
鈥?The CMOS IC boasts low current consumption &
features a backup function
鈥?18 pin dual-in-line package
鈥?Pin and function are compatible with the SMC 5242C
Absolute Max. Rating
Item
Supply voltage
Input and Output voltage
Storage temp.
Symbol
V
DD
V
I/O
T
STG
Condition
Ta=25擄C
Ta=25擄C
RTC-72421
RTC-72423
RTC-72421
RTC-72423
Specification
-0.3 ~ +7.0
GND -0.3 ~ V
DD
+0.3
-55 ~+85
-55 ~ +125
Under 260擄C within 10S (lead part)
(package should be less than 150擄C)
Under 260擄C within 10S x 2
time under 230擄C withhin 3 min
Unit
V
V
擄C
Terminal Connection
Soldering condition
T
SOL
Operating Voltage
Item
Operating voltage
Operating temperature
Data holding voltage
CSI data holding time
Operating restoring time
Symbol
V
DD
T
OPR
V
DH
t
CDR
t
R
Condition
-
-
-
Refer to the data
holding timing
Specification
4.5 ~ 5.5
-40 ~ +85
2.0 ~ 5.5
2.0 min.
Unit
V
擄C
V
碌S
Frequency and Current Consumption Characteristics
Item
Symbol
Condition
Ta=25擄C
Specification Unit
鹵10
鹵50
鹵20
鹵50
鹵10/-120
Frequency tolerance
Frequency temperature
characteristics
Aging
Shock resistance
Current consumption
鈭唂/fo
V
DD
72421A
72421B
=5V
72423A
7243B
-10 ~ +70擄C,
(25擄C reference
temperature)
ppm
ppm
Dimensions (mm)
fa
S.R.
I
DD
1
I
DD
2
V
DD
=5V, Ta25擄C, 1st year
Drop test of 3 times on a hard
board from 75cmheight of
300G x 0.3mS x 1/2 sine wave
x 3 directions
鹵5 max.
鹵5 max.
10 max.
5 Max.
ppm
ppm
碌A(chǔ)
碌A(chǔ)
CSI鈮v
V
DD
=5V
V
DD
=2V
Electrical Characteristics
Item
鈥淗鈥?Input Voltage (1)
鈥淟鈥?Input Voltage (1)
Input leakage current (1)
Input leakage current (2)
鈥淟鈥?output voltage (1)
鈥淗鈥?output voltage
鈥淟鈥?output voltage (2)
OFF leak current
Input capacity
鈥淗鈥?Input Voltage (2)
鈥淟鈥?Input Voltage (2)
Symbol Condition
V
IH1
V
IHL
I
IK1
I
LK2
V
OL1
V
OH
V
OL2
I
OFFLK
C
1
V
IH2
V
IH2
-
-
V
1
=V
DD
/0V
I
OL
=2.5mA
I
OH
=-400碌A(chǔ)
I
OL
=2.5mA
V
1
=V
DD
/0V
Input Frequency
1MHz
Min
2.2
-
Typ.
-
-
-
-
-
-
-
-
5
-
-
Max. Unit
-
0.8
1/-1
10/-10
0.4
-
0.4
10
-
-
1/5V
DD
V
碌A(chǔ)
Applicable terminal
All inputs
other than CSI
Input other than
D
2
~ D
3
D
0
~ D
3
-
-
2.4
-
-
-
V
V
碌A(chǔ)
pF
V
D
0
~ D
3
STD.P
V
DD
=2~5.5V 4/5V
DD
-
CSI
1
T E L : + 4 4 1 6 3 5 5 2 8 5 2 0 FA X : + 4 4 1 6 3 5 5 2 8 4 4 3
1
2
