DS1388 Maxim, DS1388 Datasheet - Page 8

• Manufacturer Part Number: DS1388
• Description: The DS1388 I²C real-time clock (RTC), supervisor, and EEPROM is a multifunction device that provides a clock/calendar, programmable watchdog timer, power-supply monitor with reset, and 512 bytes of EEPROM
• Manufacturer: Maxim

I
and 512 Bytes EEPROM
8
2
PIN
V
1
2
3
4
5
6
7
8
BACKUP
C RTC/Supervisor with Trickle Charger
_____________________________________________________________________
GND
SDA
SCL
V
RST
X1
X2
CC
V
NAME
BACKUP
GND
SDA
SCL
RST
V
X1
X2
CC
C
C
L
L
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 left unconnected if an external oscillator is connected to pin X1.
Connection for a Secondary Power Supply. Supply voltage must be held between 1.3V and 5.5V for proper
operation. This pin can be connected to a primary cell, such as a lithium button cell. Additionally, this pin
can be connected to a rechargeable cell or a super cap when used with the trickle-charge feature. If not
used, this pin must be connected to ground. UL recognized to ensure against reverse charging current
when used with a lithium battery (www.maxim-ic.com/qa/info/ul/).
Ground
Serial Data Output. SDA is the input/output for the I
an external pullup resistor.
Serial Clock Input. SCL is the clock input for the I
on the serial interface.
Active-Low, Open-Drain Reset Output. This pin indicates the status of V
specification. As V
pin is driven high impedance. The active-low, open-drain output is combined with a debounced
pushbutton input function. This pin can be activated by a pushbutton reset request. It has an internal
50k
crystal oscillator is disabled, the startup time of the oscillator is added to the t
DC Power Pin for Primary Power Supply
TRICKLE CHARGER
POWER CONTROL
INTERFACE
AND
nominal value pullup resistor to V
I
2
C
CC
falls below V
CLOCK AND CALENDAR
STATUS CONTROL/
WATCHDOG
REGISTERS
BLOCK 0
TRICKLE
PF
TIMER
, the RST pin is driven low. When V
CC
. No external pullup resistors should be connected. If the
FUNCTION
2
C interface and is used to synchronize data movement
2
C serial interface. This pin is open drain and requires
INTERFACE
BLOCK 1
EEPROM
EEPROM
L
) of 6.0pF. Pin X1 is the input to the
CC
CC
relative to the V
exceeds V
RST
Pin Description
Block Diagram
delay.
PF
EEPROM
DS1388
, for t
BLOCK 2
PF
RST
, the RST