Real time clock module
Product Number (Please contact us)
RTC-72421 : Q42724212xxxx00
RTC-72423 : Q42724232xxxx00
REAL TIME CLOCK MODULE (4-bit)
RTC - 72421
RTC - 72423
Built-in
crystal unit allows adjustment-free efficient operation.
24
h /12 h changeable and leap year automatically adjustable
(Gregorian calendar).
Actual size
RTC-72421
RTC-72423
Block diagram
RTC-72421/72423
OS C
D3
D2
D1
D0
R E S E T STOP
bit
bit
30 sec A D J
bit
S1
Gate
S10
C ounter
H OLD
bit
BUSY
bit
Gate
24/12
bit
WR
RD
M I1
M I10
H1
H 10
W
A3
A2
A1
A0
CS0
A LE
CS1
S1 to
CF
Latch
Decoder
D1
D10
M O1 M O10
Y1
Y10
Output
S elector
CD
CE
64 H z
1 S econd carry
C F 1 M inute carry
1 H our carry
STD .P
Terminal connection/External dimensions
RTC-72421 (DIP 18-pin)
No.
23.1 Max.
#18
#10
(Unit:mm)
RTC-72423 (SOP 24-pin)
6.3
RTC72421 A
EPSON
#1
#9
#1
#12
7.62
0.2 4.2
Min. Max.
3.3
Min.
0.25
0 -15
7.9
1234A
1
2
3
4
5
6
7
8
9
Pin
terminal
STD.P
/CS
0
ALE
A
0
A
1
A
2
A
3
/RD
GND
No.
18
17
16
15
14
13
12
11
10
Pin
terminal
V
DD
(V
DD
)
(V
DD
)
CS
1
C
0
D
1
D
2
D
3
/W R
16.3 Max.
#24
#13
No.
1
2
3
4
5
6
7
8
9
10
11
12
0.2
RTC72423
RTC62423
EPSON 1234A
Pin
terminal
STD.P
/CS
0
N.C.
ALE
A
0
N.C.
A1
N.C.
A
2
A
3
/RD
GND
No.
24
23
22
21
20
19
18
17
16
15
14
13
Pin
terminal
V
DD
(V
DD
)
(V
DD
)
N.C.
CS
1
D
0
N.C.
N.C.
D
1
D
2
D
3
/W R
1.52
0.46
2.54
1.27
0.35
0.1 Min.
12.2 Max.
2.8 Max.
1.0
0 - 10
The metal cas e inside of the molding c ompound may be exposed on the top or bottom of this product.
This purely cos metic and does not have any effect on quality, reliability or electric al specs.
Specifications (characteristics)
Absolute Max. rating
Item
Supply voltage
Input voltage
Storage
temperature
*
Symbol
V
DD
V
I/O
T
STG
Conditions
T
a
=+25
C
T
a
=+25
C
RTC-72421
RTC-72423
Min.
-0.3
GND-0.3
-55
-55
Max.
+7.0
V
DD
+0.3
+85
+125
Unit
V
C
*Refer
to application manual for details.
DC characteristics
Item
Current consumption
HIGH input voltage (1)
LOW input voltage (1)
LOW output voltage (1)
HIGH output voltage
Symbol
I
DD1
I
DD2
V
IH1
V
IL1
V
OL1
V
OH
V
OL2
I
OFFLK
C
1
V
IH2
V
IL2
I
LK1
I
LK2
Conditions
CS
1
= 0 V
V
DD
=5 V
Exclude input/
output current V
DD
=2 V
-
I
OL
=2.5 mA
I
OH
=-400 µA
I
OL
=2.5 mA
V
1
=V
DD
/0 V
Input frequency
1 MHz
V
DD
=2.0 V to 5.5 V
V
1
=V
DD
/0 V
-
10
20
4/5 V
DD
-
-
-
1/5 V
DD
1/-1
10/-10
-
Min.
-
2.2
-
-
2.4
-
Typ.
1
0.9
Max.
10
5
-
0.8
0.4
-
0.4
10/-10
V
A
pF
V
A
D
0
to D
3
STD.P
Input other than
D
0
to D
3
D
0
to D
3
, STD.P
CS
1
Input other than
D
0
to D
3
D
0
to D
3
Unit Applicable terminal
-
A
-
V
All inputs other than
CS
1
*Stored
as bare product after unpacking
Operating range
Item
Power voltage
Clock voltage
Operating
temperature
Symbol
V
DD
V
CLK
T
OPR
Conditions
-
-
RTC-72421
RTC-72423
Min.
4.5
2.0
-10
-40
Max.
5.5
5.5
+70
+85
Unit
V
LOW output voltage (2)
OFF leak current
Input capacity
C
HIGH input voltage (2)
LOW input voltage (2)
Input leak current (1)
Stored as bare produc after unpacking
Frequency characteristics
Item
Frequency
precision
Frequency
temperature
characteristics
Frequency voltage
characteristics
Symbol
f
/f
TOP
f/V
fa
Conditions
72421A
72421B
T
a
=+25 °C
V
DD
=5.0 V
72423A
72423B
-10
C
to +70
C
(+25
C)
-40
C
to +85
C(+25 C)
Range
10
50
20
50
+10 / -120
+10 / -220
Unit
Input leak current (2)
10
-6
T
a
=+25
C,V
DD
=2.0 V to 5.5 V
5.0
Max.
10
-6
/V
T
a
=+25
C,V
DD
=5.0 V,First year
5.0
Max.
10
-6
/year
Aging
PROMOTION OF ENVIRONMENTAL MANAGEMENT SYSTEM
CONFORMING TO INTERNATIONAL STANDARDS
At Seiko Epson, all environmental initiatives operate under the
Plan-Do-Check-Action (PDCA) cycle designed to achieve continuous
improvements. The environmental management system (EMS)
operates under the ISO 14001 environmental management standard.
All of our major manufacturing and non-manufacturing sites, in
Japan and overseas, completed the acquisition of ISO 14001
certification.
ISO 14000 is an international standard for environmental
management that was established by the International
Standards Organization in 1996 against the background of
growing concern regarding global warming, destruction of
the ozone layer, and global deforestation.
WORKING FOR HIGH QUALITY
In order provide high quality and reliable products and services
than meet customer needs,
Seiko Epson made early efforts towards obtaining ISO9000 series
certification and has acquired ISO9001 for all business
establishments in Japan and abroad. We have also acquired ISO/TS
16949 certification that is requested strongly by major automotive
manufacturers as standard.
►Explanation
of the mark that are using it for the catalog
►Pb
free.
►Complies
with EU RoHS directive.
*About the products without the Pb-free mark.
Contains Pb in products exempted by EU RoHS directive.
(Contains Pb in sealing glass, high melting temperature type solder or other.)
►Designed
for automotive applications such as Car Multimedia, Body Electronics, Remote Keyless Entry etc.
►Designed
for automotive applications related to driving safety (Engine Control Unit, Air Bag, ESC etc ).
ISO/TS16949 is the international standard that added the
sector-specific supplemental requirements for automotive
industry based on ISO9001.
Notice
This material is subject to change without notice.
Any part of this material may not be reproduced or duplicated in any form or any means without the written permission of Seiko Epson.
The information about applied circuitry, software, usage, etc. written in this material is intended for reference only. Seiko Epson does
not assume any liability for the occurrence of infringing on any patent or copyright of a third party. This material does not authorize the
licensing for any patent or intellectual copyrights.
When exporting the products or technology described in this material, you should comply with the applicable export control laws and
regulations and follow the procedures required by such laws and regulations.
You are requested not to use the products (and any technical information furnished, if any) for the development and/or manufacture of
weapon of mass destruction or for other military purposes. You are also requested that you would not make the products available to
any third party who may use the products for such prohibited purposes.
These products are intended for general use in electronic equipment. When using them in specific applications that require extremely
high reliability, such as the applications stated below, you must obtain permission from Seiko Epson in advance.
/ Space equipment (artificial satellites, rockets, etc.) / Transportation vehicles and related (automobiles, aircraft, trains,
vessels, etc.) / Medical instruments to sustain life / Submarine transmitters / Power stations and related / Fire work equipment
and security equipment / traffic control equipment / and others requiring equivalent reliability.
All brands or product names mentioned herein are trademarks and/or registered trademarks of their respective.
Seiko Epson Corporation
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