HT1382
I2C/3-Wire Real Time Clock
Block Diagram
Internal
power supply
VDD
VCOMP
Switch
RTC Register
VBAT
X1
X2
Crystal
Oscillator
Oscillator
Compensation
Control & Status
Register
Divider
Circuit
Alarm Register
IRQ/FOUT
CE
I2C or 3-wire
Interface
SCL/SCLK
SDA/I/O
DT & USER
EEPROM
IFS
VSS
Note: IFS pin is used for selecting I2C interface or 3-wire interface.
I2C interface is selected when IFS is unconnected.
3-wire interface is selected when IFS is connected to VSS.
Pin Assignment
2
3
-
W
i
r
e
I
n
t
e
r
f
a
c
e
I
C
I
n
t
e
r
f
a
c
e
X
1
V
I
S
I
N
D
C
D
L
1
0
1
2
3
4
5
X
1
V
I
S
S
D
D
X
2
R
/
Q
/
F
O
U
T
9
8
7
6
1
2
3
4
8
7
6
5
X
2
R
Q
/
F
O
U
T
V
B
A
T
K
V
B
A
T
C
D
L
A
C
E
O
V
S
S
V
S
S
C
H
T
1
3
8
2
H
T
1
3
8
2
8
D
I
P
-
A
/
S
O
P
-
A
/
M
S
O
P
-
1
A
0
M
S
O
P
-
A
Rev. 1.40
2
May 27, 2011
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
