DS1374C-18- MAXIM [Maxim Integrated Products], DS1374C-18- Datasheet - Page 8

• Manufacturer Part Number: DS1374C-18-
• Description: I2C, 32-Bit Binary Counter Watchdog RTC with Trickle Charger and Reset Input/Output
• Manufacturer: MAXIM [Maxim Integrated Products]

I
Trickle Charger and Reset Input/Output
Figure 4. Functional Diagram
8
µSOP
2
1, 2
10
—
3
4
5
6
7
8
9
C, 32-Bit Binary Counter Watchdog RTC with
_____________________________________________________________________
PIN
5–12
SO
13
14
15
16
—
1
2
3
4
V
V
BACKUP
NAME
X1, X2
BACKUP
GND
SQW
SDA
SCL
N.C.
RST
V
GND
SDA
INT
SCL
V
CC
CC
X1
X2
Connections for a Standard 32.768kHz Quartz Crystal. The internal oscillator circuitry is designed for
operation with a crystal having a specified load capacitance (C
oscillator and can optionally be connected to an external 32.768kHz oscillator. The output of the internal
oscillator, pin X2, is floated if an external oscillator is connected to pin X1.
Connection for a Secondary Power Supply. This supply is used to operate the oscillator and counters
when V
(-33) for proper operation. This pin can be connected to a primary cell such as a lithium cell.
Additionally, this pin can be connected to a rechargeable cell or a super cap when used with the trickle-
charge feature. UL recognized to ensure against reverse charging when used with a lithium battery. This
pin must be grounded if not used.
Active-Low, Open-Drain Output with a Debounced Pushbutton Input. This pin can be activated by a
pushbutton reset request, a watchdog alarm condition, or a power-fail event. It has an internal 50kΩ
pullup resistor. No external resistors should be connected. If the crystal oscillator is disabled, the startup
time of the oscillator is added to the t
Ground
Serial Data Input/Output. SDA is the input/output for the 2-wire serial interface. The SDA pin is open
drain and requires an external pullup resistor.
Serial Clock Input. SCL is the clock input for the 2-wire serial interface and is used to synchronize data
movement on the serial interface.
Interupt. This pin is used to output the alarm interrupt or the watchdog reset signal. It is active-low open
drain and requires an external pullup resistor.
Square-Wave Output. This pin is used to output the programmable square-wave signal. It is open drain
and requires an external pullup resistor.
DC Power for Primary Power Supply
No Connection. Must be connected to ground.
INTERFACE
CONTROL
TRICKLE
CHARGE
DIVIDER
CLOCK
POWER
2-WIRE
AND
CC
is absent. Supply voltage must be held between 1.3V and 3.7V (-18 and -3) or 1.3V and 5.5V
32.768kHz
WATCHDOG
STAT/CTRL/
4.096kHz
8.192kHz
COUNTER
TRICKLE
ALARM/
32-BIT
1Hz
RST
delay.
MUX
FUNCTION
DS1374
COUNTER
24-BIT
1Hz/4.096kHz
L
) of 6pF. Pin X1 is the input to the
CONTROL
CONTROL
RST
INT
Pin Description
INT
SQW
RST