DS1337 I

5 of 15

PIN DESCRIPTION

PIN

8

16

NAME

FUNCTION

1

—

X1

2

—

X2

Connections for a Standard 32.768kHz Quartz Crystal. The internal

oscillator circuitry is designed for operation with a crystal having a specified

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.

3

14

INTA

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.

4

15

GND

Ground. DC power is provided to the device on this pin.

5

16

SDA

Serial Data Input/Output. SDA is the input/output pin for the I

interface. The SDA pin is open-drain output and requires an external pullup

resistor.

6

1

SCL

Serial Clock Input. SCL is used to synchronize data movement on the serial

interface.

7

2

SQW/

INTB

Square-Wave/Interrupt Output. Programmable square-wave or interrupt

output signal. It is an open-drain output and requires an external pullup

resistor.

8

3

DC Power. DC power is provided to the device on this pin.

—

4–13

N.C.

No Connect. These pins are not connected internally, but must be

grounded for proper operation.

TIMING DIAGRAM