IDT1337
REA LTIME CLOCK WITH SERIAL INTERFACE
RTC
Pin Assignment
(8-pin MSOP/SOIC)
X1
X2
INTA
GND
1
2
3
4
8
VCC
SQW/INTB
SCL
SDA
Pin Assignment
(16-pin SOIC)
SCL
SQW/INTB
VCC
NC
NC
NC
NC
NC
1
2
3
4
5
6
7
8
16
15
14
SDA
GND
INTA
NC
NC
NC
NC
NC
IDT1337
7
6
5
IDT1337C
13
12
11
10
9
Pin Descriptions
Pin
Number
MSOP SOIC
1
2
—
—
Pin
Name
X1
X2
Pin Description/Function
Connections for standard 32.768 kHz quartz crystal. The internal oscillator circuitry is
designed for operation with a crystal having a specified load capacitance (CL) of 7 pF. An
external 32.768 kHz oscillator can also drive the IDT1337. In this configuration, the X1 pin
is connected to the external oscillator signal and the X2 pin is left floating.
Interrupt output. When enabled, INTA is asserted low when the time/day/date matches the
values set in the alarm registers. This pin is an open-drain output and requires an external
pull-up resistor (10 kΩ typical).
Connect to ground. DC power is provided to the device on these pins.
Serial data input/output. SDA is the input/output pin for the I
2
C serial interface. The SDA pin
is an open-drain output and requires an external pull-up resistor (2 kΩ typical).
Serial clock input. SCL is used to synchronize data movement on the serial interface. The
SCL pin is an open-drain output and requires an external pull-up resistor (2 kΩ typical).
3
4
5
6
14
15
16
1
INTA
GND
SDA
SCL
7
2
Square-Wave/Interrupt output. Programmable square-wave or interrupt output signal. The
SQW/INT pin is an open-drain output and requires an external pull-up resistor (10 kΩ
SQW/INTB
typical). This pin can also function as an additional interrupt pin under certain conditions
(see page 6 for details).
VCC
NC
Primary power supply. DC power is applied to this pin.
No connect. These pins are unused and must be connected to ground.
8
—
3
4 - 13
IDT™
REAL-TIME CLOCK WITH I
2
C SERIAL INTERFACE
2
IDT1337
REV J 111009
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
