DS1672

7 of 15

PIN DESCRIPTION

PIN

NAME

FUNCTION

1, 2

X1, X2

Connections for 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. The DS1672 can also be driven

by an external 32.768kHz oscillator. In this configuration, the X1 pin is

3

Battery Input for Any Standard 3V Lithium Cell or Other Energy Source.

Battery voltage must be held between 1.3V and 3.63V for proper operation.

grounded. UL recognized to ensure against reverse charging current when used

in conjunction with a lithium battery (charger disabled). See “Conditions of

Acceptability” at www.maxim-ic.com/qa/info/ul.

4

GND

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

5

SDA

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

6

SCL

serial interface and requires an external pullup resistor.

7

RST

Active-Low Reset Output. It functions as a microprocessor reset signal. This

pin is an open-drain output and requires an external pullup resistor.

8

limits, the device is fully accessible and data can be written and read. When

Figure 3. Recommended Layout for Crystal

LOCAL GROUND PLANE (LAYER 2)

CRYSTAL

X1

X2

GND