DS1337 I2C Serial Real-Time Clock
PIN DESCRIPTION
PIN
NAME
FUNCTION
8
16
Connections for a Standard 32.768kHz Quartz Crystal. The internal
oscillator circuitry is designed for operation with a crystal having a specified
load capacitance (CL) of 6pF. For more information about crystal selection
and crystal layout considerations, refer to Application Note 58: Crystal
Considerations with Dallas Real-Time Clocks. An external 32.768kHz
oscillator can also drive the DS1337. In this configuration, the X1 pin is
connected to the external oscillator signal and the X2 pin is floated.
1
—
X1
2
—
X2
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 pullup resistor.
3
4
5
14
15
16
INTA
GND
SDA
Ground. DC power is provided to the device on this pin.
Serial Data Input/Output. SDA is the input/output pin for the I2C serial
interface. The SDA pin is open-drain output and requires an external pullup
resistor.
Serial Clock Input. SCL is used to synchronize data movement on the serial
interface.
Square-Wave/Interrupt Output. Programmable square-wave or interrupt
output signal. It is an open-drain output and requires an external pullup
resistor.
6
7
1
2
SCL
SQW/INTB
8
3
VCC
DC Power. DC power is provided to the device on this pin.
No Connect. These pins are not connected internally, but must be
grounded for proper operation.
—
4–13
N.C.
TIMING DIAGRAM
5 of 15
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
