Epson RX8130 CE Instructions for use

ETM50E-05
Preliminary
Application Manual
Real Time Clock Module
RX8130 CE

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.

ETM50E Revision History
Rev No.
Date
Page
Description
ETM50E-01
--
--
ETM50E-02
05.Oct.2015
Release
ETM50E-03
10.May.2016
1
Corrected a the block diagram.
4
Add description to [3.2. Pin Functions].
9
Corrected a [10.1. Characteristic for the fluctuation of the power
supply ]
13
Corrected a [7) Clock output function]
27
Corrected a [14.7.2. Related register of Battery backup
switchover function]
ETM50E-04
20.Sep.2016
3
Updated the Recommended soldering pattern
Optimization of the text.
ETM50E-05
23.Jan.2018
2
Added terminal processing when output terminal is not used.
3
Added typical value of external dimensions.
3
Added recommended soldering pattern.
6
Corrected Max. value of Hihgh- Level input voltage.
8
Corrected reset delay time (at recovery form backup).
9
Corrected access wait time.
20
Changed 7) TSTP bit related table.
21
Added timer circuit block diagram
25
Added alarm circuit block diagram
27
Added time update circuit block diagram
30
Corrected table operation stages of voltage detection.
36
Added comment to wait time.
37
Added comments related to STOP bit in 3)The setting of the
clock and calendar.
42
Added address circulation table of auto increment function.

RX8130 CE
ETM50E-05
Contents
1. Overview........................................................................................................................1
2. Block Diagram ...............................................................................................................1
3. Terminal description .....................................................................................................2
4. Examples of external connection...................................................................................2
5. External Dimensions / Marking Layout...........................................................................3
6.Absolute Maximum Ratings...........................................................................................4
7. Recommended Operating Conditions............................................................................4
8. Frequency Characteristics.............................................................................................4
9.Electrical Characteristics ..............................................................................................5
10. Matters that demand special attention on use..............................................................9
11. Reference information ...............................................................................................11
12. Application notes .......................................................................................................12
13. Overview of Functions and Description of Registers................................................13
13.1. Overview of Functions..................................................................................................................13
13.2. Register table ...............................................................................................................................14
13.3. Description of registers.................................................................................................................15
14. How to use.................................................................................................................17
14.1. Clock calendar explanation ..........................................................................................................17
14.2. Fixed-cycle Timer Interrupt Function............................................................................................18
14.3. Alarm Interrupt Function...............................................................................................................23
14.4. Time Update Interrupt Function....................................................................................................26
14.5. Frequency stop detection function ...............................................................................................28
14.6.FOUT function [clock output function] ..........................................................................................28
14.7. Battery backup switchover function..............................................................................................28
14.8. Reset output function ...................................................................................................................33
14.9. Detection voltage setting..............................................................................................................34
14.10. Digital offset function..................................................................................................................34
14.11. Flow-chart...................................................................................................................................36
14.12. Reading/Writing Data via the I2C Bus Interface .........................................................................40

RX8130CE
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ETM50E-05
Build-in backup battery charge control function
SERIAL-INTERFACE REAL TIME CLOCK MODULE
RX8130CE
•Built in frequency adjusted 32.768 kHz crystal unit.
•Interface type : I2C-Bus interface (up to 400 kHz)
•Wide operating voltage range : 1.6Vto5.5V
•Wide timekeeper voltage range : 1.1Vto5.5V
•Auto power switching function : Switchover by main power supply monitor.
•Backup battery charge control function : For rechargeable lithium batteries.
•Low leak current : A leak current from a backup power supply pin. 5nA (Max.)
•Reset function : At low supply voltage, external reset signal is generated.
•Low voltage detection : supply voltage and backup voltage detection
•Time correction : digital offset function
•The various function include full calendar, alarm, timer, etc.
The I2C-Bus is a trademark of NXP Semiconductors.
1. Overview
This is a real-time clock module of the serial interface system that incorporates a 32.768 kHz crystal oscillator.
The real-time clock function incorporates not only a calendar and clock counter for the year, month, day, day of the
week, hour, minute, and second, but also a time alarm, interval timer, and time update interruption, among other
features. By the backup battery charge control function and the interface power supply input pin, RX8130CE can
support various power supply circuitries.
All of these many functions are implemented in a thin, compact ceramic package, which makes it suitable for various
kinds of small electronic devices.
2. Block Diagram
VOUT
FOUT
VBAT
GND
(System
Control)
Logic Area
SDA
SCL
VDD
Reset
(Delay)
/RST
VIO
CMP
Power
Control
VBAT
Detector
(VDET1)
(VDET2)
(VDET3)
(VDET4)
（VCMP）
Register
Flag
VDD
Detector
OSC
32.768kHz
/IRQ
Divider
Divider
Clock
and
Calendar
Timer
Register
Alarm
Register
Bus
Interface
FOUT Controller
Interrupts
Controller

RX8130CE
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ETM50E-05
3. Terminal description 
3.1. Terminal connections
RX8130CE
1.
VIO
10.
VBAT
2.
SCL
9.
VOUT
3.
SDA
8.
VDD
4.
FOUT
7.
GND
5.
/RST
6.
/IRQ
3.2. Pin Functions
Signal
name
I/O
Function
SCL
Input
Serial clock input pin.
SDA
Bi-directional
Data input and output pin.
FOUT
Output
Frequency output pin with output control function. (CMOS)
Output frequency can be selected as 32.768kHz, 1024Hz, 1Hz.
/ RST
Open-Drain
Output
Even in the backup mode, this pin can opperate. In case of VDD voltage drop detection, a
reset signal is outputted.
In case of VDD voltage rise detection, it releases the reset signal after 60ms.
/ IRQ
Open-Drain
Output
Interrupt output by Alarm and Timer events.(N-ch open drain)
This pin can output even a backup mode.
VDD

This is a power-supply pin for the internal logic.
VIO

This is a interface power supply pin. (There is an level shifter between VDD and VIO)
VOUT

Internal voltage output pin.
Connect smoothing capacitor of 1.0uF
VBAT

This is a power supply pin for backup battery.
This is a pin to connect a large-capacity capacitor, a secondary battery, and a primary
battery.
In a backup mode, the voltage is supplied inside by this pin.
GND

Connected to a ground.
Note: Connect a bypass capacitor rated at least 0.1μF between power supply pins and GND pin.
Note: Input pins are able to input up to 5.5V regardless of VIO applied voltage.
Note: Open drain pins are able to Pull-up to 5.5V regardless of VIO applied voltage.
Note: Use the FOUT, /RST, /IRQ terminals as OPEN when not in use.
4. Examples of external connection
4.1. Examples of power supply connection
VDD
VBAT
VIO
VD1.8
VD3
R
0.1F
secondary
battery
EDLC
or
0.1F
1.0F
VOUT
0.1F
VDD
VBAT
VIO
VD3
VD3
R
0.1F
secondary
battery
EDLC
or
1.0F
VOUT
0.1F
VDD
VBAT
VIO
VD3
R
0.1F
Primary
battery
1.0F
VOUT
0.1F
(2) Same I/F voltage and
charge voltage
(CHGEN=1, INIEN=1)
(3) Primary battery as backup
(CHGEN=0)
(1) Case of different I/F voltage
and charge vlotage

RX8130CE
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ETM50E-05
5. External Dimensions / Marking Layout
5.1. External Dimensions
RX8130CE
•External dimensions •Recommended soldering pattern
Unit : mm
3.2 0.2 (Typ.3.24)
"CE"PKGRev.04
2.5±0.2 (Typ.2.54)
1.0Max.
0.7
0.3
0.62
0.42
0.2Min.
0.4
0.35
0.7
0.4
0.9
1.1
0.3
0.7
0.4
0.9
1.1
Type.1 (for small mounting area)
Type.2
5.2. Marking Layout
RX8130CE
#1 Pin Mark
Logo
Production lot
R8130

A123B
Type
Contents displayed indicate the general markings and display, but are not the standards for the fonts, sizes and positioning.

RX8130CE
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Page4
ETM50E-05
6.Absolute Maximum Ratings
GND=0V
Item
Symbol
Condition
Rating
Unit
Supply voltage
VDD

0.3

+6.5
V
Internal voltage
VOUT

0.3

+6.5
V
Backup supply voltage
VBAT

0.3

+6.5
V
Interface
supply voltage
VIO

0.3

+6.5
V
Input voltage 1
VIN1
SCL, SDA
0.3

+6.5
V
Output voltage 1
VOUT1
/RST, /IRQ, SDA
0.3

+6.5
V
Output voltage 2
VOUT2
FOUT
-0.3

VIO+0.3
V
Storage temperature
TSTG
When stored separately,
without packaging
55
to
+125
C
7. Recommended Operating
Conditions
*Unless otherwise specified, GND=0V,Ta=40Cto+85C 
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
Operating supply voltage
VDD
Normal operation mode (VDD)
1.25
3.0
5.5
V
Interface supply voltage
VIO
VDD=VDET1 5.5V
The interface halts
when VDD becomes less than VDET1.
1.6
3.0
5.5
V
Clock supply voltage
VCLK
Backup operation mode (VBAT)
1.1
3.0
5.5
V
Operating temperature
T_use
No condensation
40
+25
+85
C
Minimum value of Clock supply voltage VCLK is the timekeeping continuation lower limit value that initialized RX8130 in operating
supply voltage VDD.
8. Frequency Characteristics
*Unless otherwise specified, GND=0V,Ta=40Cto+85C
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
Output frequency
fo
32.768
(Typ.)
kHz
Frequency stability
f/f
Ta=+25C
VDD=3.0V
523
(1)
106
Frequency/voltage
characteristics
f/V
Ta=+25C
VDD=1.1V5.5V
2
+2
106/V
Frequency/temperature
characteristics
Top
Ta=20C+70C
VDD=3.0V;+25C reference
120
+10
106
Oscillation start time
t_str
VDD=2.75V5.5V
Internal X'tal oscillation start
0.19
1.0
s
Aging
fa
Ta=+25C,VBAT=3.0V;
first year
5
+5
106
/year
1 ) The monthly error is equal to 60 seconds. ( excluding offset )

RX8130CE
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ETM50E-05
9.Electrical Characteristics
9.1.DC characteristics
*Unless otherwise specified, GND=0V,Ta=40Cto+85C
9.1.1.DC characteristics(1)
*Unless otherwise specified, GND =0V,VBAT=VDD=1.1V5.5V,VIO=1.6V5.5V,
Ta=40C +85C 
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
Current consumption in
normal operation mode
without FOUT (1)
IDD
SCL=SDA = ”H” ,
FOUT=OFF, /IRQ=OFF,
VDD=VIO=3.0V, -40C+85C
CHGEN=0b or VBAT≧VDET3
1500
1600
nA
Current consumption in
normal operation with
FOUT (2)
I32k
SCL=SDA = ”H” ,
FOUT=32.768kHz, /IRQ=OFF,
VDD=VIO=3.0V, -40C+85C
FOUT pin CL=15pF
CHGEN=0b or VBAT≧VDET3
3.5
4.0
uA
Current consumption in
backup mode(3)
IBAT
SCL=SDA = ”L” ,
VBAT=3.0V ,VDD=VIO=0.0V, -40C+85C
300
500
nA
Detector Threshold
Voltage1
(rising edge of VDD )
+VDET11
2.75V setting Reset-releases
2.72
2.80
2.88
V
Detector Threshold
Voltage1
(falling edge of VDD )
-VDET11
2.75V setting、Reset output
2.67
2.75
2.83
V
Detector Threshold
Voltage2
(rising edge of VDD )
+VDET12
2.7V setting Reset-releases
2.67
2.75
2.83
V
Detector Threshold
Voltage2
(falling edge of VDD )
-VDET12
2.7V setting , Reset output
2.62
2.70
2.78
V
Detector Threshold
Voltage3
(rising edge of VDD )
+VDET2
Switching voltage from VBAT to VDD
1.25
1.35
1.45
V
Detector Threshold
Voltage3
(falling edge of VDD )
-VDET2
Switching voltage from VDD to VBAT
1.20
1.30
1.40
V
Detector Threshold
Voltage1
(rising edge of VBAT)
+VDET31
Charge stop voltage (full charge)
BFVSEL=00b
2.94
3.02
3.10
V
Detector Threshold
Voltage1
(falling edge of VBAT)
-VDET31
Recharge voltage.
BFVSEL=00b
2.89
2.97
3.05
V
Detector Threshold
Voltage2
(rising edge of VBAT)
+VDET30
Charge stop voltage (full charge)
BFVSEL=10b
2.84
2.92
3.00
V
Detector Threshold
Voltage2
(falling edge of VBAT)
-VDET30
Recharge voltage.
BFVSEL=10b
2.79
2.87
2.95
V
Detector Threshold
Voltage3
(rising edge of VBAT)
+VDET32
Charge stop voltage (full charge)
BFVSEL=01b
3.00
3.08
3.16
V
Detector Threshold
Voltage3
(falling edge of VBAT)
-VDET32
Recharge voltage.
BFVSEL=01b
2.95
3.03
3.11
V
VBAT end voltage
-VDET4
Low VBATdetection
Register flag VBLF = 1b
2.32
2.40
2.48
V
VDD-VOUT
off-leak current
ISW1
VOUT=3.0V、VDD=0.0V
5.0
nA
VBAT-VOUT
off-leak current
ISW2
VBAT=3.0V、VOUT=0.0V
5.0
nA

RX8130CE
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ETM50E-05
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
VOUT output voltage 1
VVOUT1
VDD=3.0V、IOUT=1mA
VDD-0.06
V
VOUT output voltage 2
VVOUT2
VBAT=3.0V、IOUT=0.1mA
VBAT-0.02
V
High-level
input voltage
VIH1
SCL, SDA
0.8 VIO
5.5
V
Low-level
input voltage
VIL
SCL, SDA
GND 0.3
0.2 VIO
V
High-level
output voltage
VOH
FOUT
IOH=-1 mA
VIO–0.5
VIO
V
Low-level
output voltage
VOL1
FOUT
IOL=1 mA
GND
GND+0.5
V
VOL2
/RST,/IRQ
VIO=5 V, IOL=1 mA
GND
GND+0.25
V
VOL3
VIO=3 V, IOL=1 mA
GND
GND+0.4
V
VOL4
SDA
VIO 2 V, IOL=3 mA
GND
GND+0.4
V