Actual size
Real time clock module
Block diagram
Terminal connection/External dimensions
(
Unit:mm
)
S
p
ecifications
(
characteristics
)
*Refer to a
pp
lication manual for details.
Absolute Max. rating DC characteristics
Item Symbol Condition Min. Max. Unit Item Symbol Condition Min. Typ. Max. Unit Applicable terminal
Supply voltage VDD Ta=+25 C -0.3 +7.0 V Current consumption IDD1 CS1= 0 V
Exclude input/
output current
VDD=5 V
-
1 10
A
-
Input voltage VI/O Ta=+25 C GND-0.3 VDD+0.3 IDD2 VDD=2 V 0.9 5
-
Storage
temperature * TSTG RTC-72421 -55 +85 C HIGH input voltage (1) VIH1
-
2.2
-
-
V All inputs other than
CS1
RTC-72423 -55 +125 LOW input voltage (1) VIL1
-
0.8
*Stored as bare product after unpacking LOW output voltage (1) VOL1 IOL=2.5 mA
-
0.4
V D0 to D3
Operating range HIGH output voltage VOH IOH=-400 µA 2.4
-
Item Symbol Condition Min. Max. Unit LOW output voltage (2) VOL2 IOL=2.5 mA
-
0.4 STD.P
Power voltage VDD
-
4.5 5.5 V OFF leak current IOFFLK V1=VDD/0 V 10/-10 A
Clock voltage VCLK
-
2.0 5.5 Input capacity C1 Input frequency
1 MHz 10
-
pF Input other than
D0 to D3
Operating
temperature TOPR RTC-72421 -10 +70 C 20 D0 to D3, STD.P
RTC-72423 -40 +85 HIGH input voltage (2) VIH2 VDD=2.0 V to 5.5 V 4/5 VDD
-
V CS1
S tored as bare produc after unpacking LOW input voltage (2) VIL2
-
1/5 VDD
Frequency characteristics Input leak current (1) ILK1 V1=VDD/0 V
-
1/-1 AInput other than
D0 to D3
Item Symbol Condition Range Unit Input leak current (2) ILK2 10/-10 D0 to D3
Frequency
precision f /f Ta=+25 °C
VDD=5.0 V
72421A 10
10-6
72421B 50
72423A 20
72423B 50
Frequency
temperature
characteristics TOP -10 C to +70 C (+25 C) +10 / -120
-40 C to +85 C(+25 C) +10 / -220
Frequency voltage
characteristics f/V Ta=+25 C,VDD=2.0 V to 5.5 V 5.0 Max. 10-6/V
Aging fa
Ta=+25 C,VDD=5.0 V,First year 5.0 Max. 10-6/year
OSC
RESET
bit STOP
bit
30 sec ADJ
bit
Counter
HOLD
bit BUSY
bit
D3
D2
D1
D0
WR
RD
A3
A2
A1
A0
CS0
ALE
CS1
S1 S10 MI1 MI10 H1 H10 W
D1 D10 MO1 MO10 Y1 Y10
64 Hz
1 Second carry
1 Minute carry
1 Hour carry
S1 to
CF
CD CE CF
Gate
Gate
Latch Decoder
24/12
bit
RTC-72421/72423
STD.P
Output
Selector
RTC-72421 RTC-72423
4-bit REAL TIME CLOCK MODULE
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).
Metal may be exposed on the top or bottom of this product. This will not affect an y quality, reliability or electric a l s pe c .
RTC-72421 (DIP 18-pin)
7.62
0 -15 0.25
0.46
4.2
Max.
3.3
Min.
0.2
Min.
2.54
1.52
23.1 Max.
6.3
#1
#18 #10
#9
RTC72421 A
EPSON 1234A
No. Pin
terminal No. Pin
terminal
1 STD.P 18 VDD
2 /CS0 17 (VDD)
3 ALE 16 (VDD)
4 A0 15 CS1
5 A1 14 C0
6 A2 13 D1
7 A3 12 D2
8 /RD 11 D3
9 GND 10 /WR
RTC-72423 (SO P 24-pin)
1.0
0.2
0 - 10
0.2
0 - 10
1.27 0.35
2.8 Max.
0.1 Min.
2.8 Max.
0.1 Min.
#12#1
16.3 Max.
#24 #13
7.9
12.2 Max.
RTC62423
EPSON 1234A
#12#1
16.3 Max.
#24 #13
7.9
12.2 Max.
RTC72423
EPSON 1234A
No. Pin
terminal No. Pin
terminal
1 STD.P 24 VDD
2 /CS0 23 (VDD)
3 N.C. 22 (VDD)
4 ALE 21 N.C.
5 A0 20 CS1
6 N.C. 19 D0
7 A1 18 N.C.
8 N.C. 17 N.C.
9 A2 16 D1
10 A3 15 D2
11 /RD 14 D3
12 GND 13 /WR
Product Number (Please contact us)
RTC-72421 : Q42724212xxxx00
RTC-72423 : Q42724232xxxx00
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.
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.)
►The products have been designed for high reliability applications such as Automotive.
Seiko Epson Corporation
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.
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.
ISO/TS16949 is the international standard that added the
sector-specific supplemental requirements for automotive
industry based on ISO9001.
