Actual si
ze
Real time
cl
ock m
odule
www
.eea.epson.co
m
Block diagram
T
erminal conn
e
ction/External dimensions
(Uni
t
:mm
)
S
p
ecifications (characteristics)
*
Refer to app
l
ication manual for details.
A
bsol
ute Max.
r
ating
DC characteristics
Ite
m
Symbol
Condition
Min.
Max.
Unit
Ite
m
Symbol
Condition
Min.
T
yp
.
Max.
Unit
Applicable terminal
Supply voltage
V
DD
T
a
=+25
C
-0.3
+7.0
V
Current consumption
I
DD1
CS
1
= 0 V
Exclude input/
output current
V
DD
=5 V
-
1
10
A
-
I
n
put voltage
V
I/O
T
a
=+25
C
GND-0.3
V
DD
+0
.3
I
DD2
V
DD
=2 V
0.9
5
-
St
orage
tempe
r
ature
*
T
STG
RTC-72421
-
55
+85
C
HIG
H
input voltage (1)
V
IH1
-
2.2
-
-
V
All inputs othe
r
than
CS
1
RTC-72423
-
55
+125
LOW input volta
g
e (1)
V
IL1
-
0.8
*
S
tored as bare pr
o
d
uct afte
r u
npa
c
king
LOW output volta
g
e (1)
V
OL1
I
OL
=2
.5
mA
-
0.4
V
D
0
to D
3
Operating range
HIG
H
output voltage
V
OH
I
OH
=-400 µ
A
2.4
-
Ite
m
Symbol
Condition
Min.
Max.
Unit
LOW output volta
g
e (2)
V
OL2
I
OL
=2
.5 mA
-
0.4
STD.P
Power
v
oltage
V
DD
-
4.5
5.5
V
OFF
l
eak current
I
O
FFLK
V
1
=V
DD
/0
V
10/
-
10
A
Clock volta
g
e
V
CLK
-
2.0
5.5
I
n
put capacity
C
1
I
n
put frequency
1 MHz
10
-
pF
I
n
put other than
D
0
to
D
3
Operating
tempe
r
ature
T
OPR
RTC-72421
-
10
+70
C
20
D
0
to
D
3
, STD
.P
RTC-72423
-
40
+85
HIG
H
input voltage (2)
V
IH2
V
DD
=2.0
V to
5
.5 V
4/5 V
DD
-
V
CS
1
Stored as bare produc aft
er unpacking
LOW input volta
g
e (2)
V
IL2
-
1/5 V
DD
Frequency
characteristics
I
n
put leak current (1)
I
L
K1
V
1
=V
DD
/0
V
-
1/
-1
A
I
n
put other than
D
0
to
D
3
Ite
m
Symbol
Condit
i
on
Range
Unit
I
n
put leak current (2)
I
L
K2
10/
-
10
D
0
to
D
3
Frequency
precision
f /f
T
a
=+25 °C
V
DD
=5
.0 V
72421A
10
10
-6
72421B
50
72423A
20
72423B
50
Frequency
tem
per
atu
re
characteristics
TOP
-
10
C to
+7
0
C
(+25
C)
+10 / -
120
-
40
C to
+8
5
C(+25
C)
+10 / -
220
Frequency voltage
characteristics
f/V
T
a
=+25
C
,V
DD
=2.0 V to 5.5 V
5.0 Max.
10
-6
/V
Aging
fa
T
a
=+25
C
,V
DD
=5.0 V
,
First year
5.0 Max.
10
-6
/ye
ar
OSC
RESET
bit
STOP
bit
30 sec A
DJ
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 c
arry
1 Hour carry
S1 to
CF
CD
CE
CF
Gate
Gate
Latch
Dec
ode
r
24/12
bit
RTC-72421
/
72423
STD.P
Output
Selec
tor
RT
C
-72421
RT
C
-72423
4-bit REAL
TI
ME CLOCK MODULE
RT
C
-
7
2421
RT
C
-
7
2423
Built-in crystal
unit allows adjustment-free efficient
operation.
24 h
/12 h c
hangea
b
le and leap year automatically adjusta
b
le
(Greg
or
ian
c
alendar).
Metal may
be exposed on the t
op or bottom of this product. This will not affe
ct any quality
, reliability or electrical spec.
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
V
DD
2
/CS
0
17
(V
DD
)
3
ALE
16
(V
DD
)
4
A
0
15
CS
1
5
A
1
14
C
0
6
A
2
13
D
1
7
A
3
12
D
2
8
/RD
11
D
3
9
GND
10
/W
R
RTC
-72423 (SOP 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.
RT
C62
4
2
3
EPSO
N 1
2
3
4
A
#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
V
DD
2
/CS
0
23
(V
DD
)
3
N.C.
22
(V
DD
)
4
ALE
21
N.C.
5
A
0
20
CS
1
6
N.C.
19
D
0
7
A1
18
N.C.
8
N.C.
17
N.C.
9
A
2
16
D
1
10
A
3
15
D
2
11
/RD
14
D
3
12
GND
13
/W
R
Product Number
(Please contact us)
RTC-72421 : Q42724212xxxx00
RTC-72423 : Q42724232xxxx00
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