Actual size
Real time clock module
Block diagram
Overview
32kHz
OUTPUT
CONTROL
OSC
COMPARATOR_D ALARM_D REGISTER
(MIN,HOUR)
ADDRESS
DECODER
ADDRESS
REGISTER
VOLTAGE
DETECT
DIV
TIME COUNTER
(SEC,MIN,HOUR,WEEK,DAY,MONTH,YEAR)
SHIFT REGISTER
I/O
CONTROL
FOUT
INTERRUPT CONTROL
CLK
DIVIDER
CORREC
-TION
VDD
GND
COMPARATOR_W ALARM_W REGISTER
(MIN,HOUR, WEEK)
CE
OSC
DETECT D
I
/INT
DO
 Features built-in 32.768kHz cry stal unit
▪Frequency adjusted forhigh accuracy
(5106 /Ta=+25C)
(Equivalent to 13 seconds of monthly deviation)
 The various detection Function
▪Power supply voltage monitoring function
(with selectable detection threshold)
▪Stop detection function
▪Power-on reset detection function
Equipped with alarm and timer
▪Timer function produces a periodic interruption signal.
As for the Alarm function an optional combination is
produced. (Date of the week , time , minute)
Pin function
Terminal connection
External dimensions
(
Unit:mm
)
Signal
Name
Input /
Output Function
CE Input
The chip enabled input pin.
( built -in pull-down resistance )
At the "H"level, access becomes possible.
CLK Input
The shift clock input pin for serial data transfer.
DI Input
The data input pin for serial data transfer.
DO Output
The data output pin for serial data transfer.
FOUT Output
32.768kHzclock output pin with the output control
function (N-ch open drain)
High impedance at the time of output off.
/ INT Output Interrupt output (N-ch open drain)
TEST
-
Used by the manufacturer for testing.
(Do not connect externally.)
VDD
-
Connected to a positive power supply.
GND
-
Connected to a ground.
RX4045SA
1. N.C. 14. N.C.
2. CLK 13. DO
3. FOUT 12. DI
4. N.C. 11. GND
5. TEST 10. /INT
6. VDD 9. N.C.
7. CE
10.1 0.2
5.0
7.40.2
3.20.1
1.27
8. N.C.
SOP14 pin
RX4045NB
1. CE 22. N.C.
2. VDD 21. N.C.
3. (GND) 20. N.C.
4. TEST 19. N.C.
5. FOUT 18. N.C.
6. CLK 17. N.C.
7. DO 16. N.C.
8. DI 15. N.C.
9. GND 14. N.C.
10. /INT 13. 
11. N.C.
4.8
6.3Max.
5.00.2
0.5
1.30.1
12. 
SON22 pin
 The metal case inside of the molding compound may be exposed on the top or bottom of this product.
This purely cosmetic and does not have any effect on quality, reliability or electrical specs.
S
p
ecifications
(
characteristics
)
Refe
r
to a
pp
lication manual for details.
Recommended Operating Conditions
Item Symbol Conditions Min. Typ. Max. Unit
Power voltage VDD
-
1.7 3.0 5.5 V
Clock voltage VCLK
-
1.15 3.0 5.5 V
Operating
temperature TOPR
-
-40 +25 +85
C
Frequency characteristics
Item Symbol Conditions Rating Unit
Frequency
tolerance f/f Ta=+25°C
VDD=3.0V
AA: 551)
AC: 052) 106
Oscillation
start-up time tSTA Ta=+25°C
VDD=2.0V 1Max. s
Frequency / voltage
characteristics f/V Ta=+25°C
VDD=2.0Vto5.5V 1Max. 106
1)2) Equivalent to 13 seconds of monthly deviation (excluding offset.)
Current consumption characteristics Ta=40Cto+85C
Item Symbol Conditions Min. Typ. Max. Unit
Current
Consumption
IBK
CE=GND
FOUT;output OFF
(Hi-z)
VDD
=5V 0.60 1.80
µA
VDD
=3V 0.48 1.20
I32k
CE=GND
FOUT;32.768kHz
output ON
VDD
=3V 0.65 2.00 µA
Power supply detection voltage Ta=30Cto+70C
Item Symbol Conditions Min. Typ. Max. Unit
High-voltage mode VDETH VDD pin 1.90 2.10 2.30 V
Low-voltage mode VDETL VDD pin 1.15 1.30 1.45 V
RX-4045SA RX-4045NB
High-Stability Frequency
SERIAL-INTERFACE REAL TIME CLOCK MODULE
RX-4045SA/NB
Built-in 32.768 kHz crystal unit : Frequency adjusted for high accuracy.
(5106/Ta=+25C)
Interface Type : 4-wire serial interface
Operating voltage range : 1.7Vto5.5V
Wide Timekeeper voltage range : 1.15Vto5.5V
Various detection Functions : Oscillation stop detection function etc.
Low backup current : 0.48A/3V(Typ.)
32.768 kHz clock frequency output : N-ch open drain output
Function of time and calendar, the various detection function,
and interrupt function etc.
Product Number (Please contact us)
RX-4045SA : Q41404552xxxx 00
RX-4045NB : Q41404592xxxx00
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.