Real time clock module
Epson Toyocom
High-Stability
I2C-Bus INTERFACE REAL TIME CLOCK MODULE
RX - 8025 SA NB
/
•Built-in 32.768 kHz crystal unit
: Frequency adjusted for high accuracy
(± 5 ×10−6 / T
= +25 °C)
: I2C-Bus Interface (400 kHz)
•Operating voltage range: 1.70 V to 5.5 V
a
•Interface Type
•Wide Timekeeper voltage range
•Various detection Functions
•Low backup current
: 1.15 V to 5.5 V
: Ex. Oscillation stop detection function
: 0.48 µA / 3 V (Typ.)
Actual size
RX-8025SA
•32.768 kHz frequency output function : C-MOS output With Control Pin
•The various functions include full calendar, alarm, timer.
RX-8025NB
* The I2C-Bus is a trademark of NXP Semiconductors
Block diagram
Overview
• Features built-in 32.768 kHz crystal unit
• Frequency adjusted for high accuracy.
Alarm_W Register
( Min,Hour,Week )
Comparator_W
Comparator_D
FOUT
FOE
( ± 5 ×10−6
/
Ta = +25 °C )
32 kHz
Output
Control
V
DD
Voltage
Detect
( Equivalent to 13 seconds of monthly deviation )
Alarm_D Register
( Min,Hour )
• The various detection function
• Power supply voltage monitoring function
(with selectable detection threshold )
• Stop detection function
Divider
Correc
-tion
Time Counter
( Sec,Min,Hour,Week,Day,Month,Year )
Div.
OSC
• Power-on reset detection function
• Alarm function and Timer function
• Timer function produces a periodic interruption signal.
As for the Alarm function an optional combination is produced.
(Date of the week , time , minute)
Address
Decoder
Address
Register
SCL
OSC
Detect
I/O
Control
SDA
GND
/ INTA
/ INTB
Interrupt Control
Shift Register
Pin Function
Terminal connection / External dimensions
(Unit:mm)
Signal
Name
SCL
−
−
RX 8025 SA
RX 8025 NB
Input / output
Input
Bi-directional Data input and output pin
Function
Serial clock input pin
N.C.
22.
1. FOE
2. VDD
1. N.C.
2. SCL
3. FOUT
4. N.C.
5. TEST
6. VDD
7. FOE
14. N.C.
13. SDA
12. / INTB
11. GND
SDA
N.C.
21.
32.768 kHz clock output pin with the output
control function. (C-MOS)
3. (GND)
4. TEST
5. FOUT
6. SCL
7. SDA
20. N.C.
FOUT
FOE
Output
Input
N.C.
19.
FOE
input
L
/CLEN1 /CLEN2
FOUT
output
bit
X
0
bit
X
0
N.C.
N.C.
N.C.
N.C.
N.C.
−
18.
17.
16.
15.
14.
13.
12.
OFF ( LOW )
32.768 kHz
32.768 kHz
32.768 kHz
OFF(LOW)
0
1
1
0
5.0
H
4.8
10.
9. N.C.
8. N.C.
/ INTA
1
1
8.
9. GND
10.
11. N.C.
/ INTB
±
1.3 0.1
/ INTA
/ INTB
Output
Output
Interrupt output A pin ( N-ch open drain )
Interrupt output B pin ( N-ch open drain )
/ INTA
±
0.2
7.4
± 0.2
5.0
Used by the manufacture for testing.
(Do not connect externally.)
−
TEST
SOP 14 pin
−
SON 22 pin
−
VDD
Connected to a positive power supply.
Connected to a ground.
GND
Metal may be exposed on the top or bottom of this product. This will not affect any quality, reliability or electrical spec.
Specifications (characteristics)
Refer to application manual for details.
.
!
!
Current consumption characteristics
Recommended Operating Conditions
Ta = 40 C to +85 C
− ° °
Item
Symbol
Condition
SCL
= 0Hz
Min. Typ. Max. Unit
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
DD
V
V
DD
V
Power voltage
Clock voltage
Operating
3.0
3.0
5.5
5.5
V
V
1.7
1.15
f
0.60 1.80
µA
0.48 1.20
CLK
= 5 V
DD
V
FOE = GND
FOUT ; output
OFF(LOW)
SCL
BK
I
OPR
T
−
40
°
C
+25
+85
temperature
= 3 V
Curent
Consumption
f
= 0Hz
!
Frequency characteristics
DD
V
DD
V
, FOE = 5.5 V
32k
= 5.5 V
I
3.0
6.5
µA
FOUT ; output ON
( Output=OPEN;
CL = 0 pF )
Item
Symbol
Condition
Range
Unit
1)
2)
a
°
±
±
Frequency
tolerance
Oscillation
start-up time
Frequency voltage
characteristics
T
V
T
V
= +25
C
AA: 5
AC: 0
5
5
6
6
−
∆
×
f / f
10
s
DD
= 3.0 V
a
°
C
= +25
STA
t
!
Power supply detection voltage
1 Max.
Ta = −30 °C to +70 °C
DD
= 2.0 V
a °
T = +25 C
Item
Symbol
Condition
Min. Typ. Max. Unit
−
±
×
10
f / V
1 Max.
DD
V
= 2.0 V to 5.5 V
DETH
V
DD
High-voltage mode
Low-voltage mode
V
pin
pin
1.90 2.10 2.30
1.15 1.30 1.45
V
V
1) 2) Equivalent to 13 seconds of monthly deviation (excluding offset).
DETL
V
DD
V
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