ISL12029_1012 Datasheet, PDF (2/29 Pages) Intersil Corporation – Real Time Clock/Calendar with I2C Bus™ and EEPROM

Block Diagram
ISL12029, ISL12029A
X1
32.768kHZ
X2
IRQ/F_OUT
SELECT
SCL
SDA
SERIAL
INTERFACE
DECODER
CONTROL
DECODE
LOGIC
8
RESET
OSC COMPENSATION
OSCILLATOR
FREQUENCY
DIVIDER
1Hz
TIMER
CALENDAR
LOGIC
TIME
KEEPING
REGISTERS
(SRAM)
CONTROL/
REGISTERS
(EEPROM)
STATUS
REGISTERS
(SRAM)
ALARM
WATCHDOG LOW VOLTAGE
TIMER
RESET
COMPARE
ALARM REGS
(EEPROM)
4k
EEPROM
ARRAY
BATTERY
SWITCH
CIRCUITRY
V_DD
V_BACK
Pin Descriptions
PIN
NUMBER
1
SYMBOL
X1
DESCRIPTION
The X1 pin is the input of an inverting amplifier and is intended to be connected to one pin of an external 32.768kHz
quartz crystal.
2
6
7
8
9
12
13
14
3, 4, 5, 10,
11
X2
The X2 pin is the output of an inverting amplifier and is intended to be connected to one pin of an external 32.768kHz
quartz crystal.
RESET
RESET. This is a reset signal output. This signal notifies a host processor that the “Watchdog” time period has
expired or that the voltage has dropped below a fixed V_TRIP threshold. It is an open drain active LOW output.
Recommended value for the pull-up resistor is 5kΩ. If unused, connect to ground.
GND
Ground.
SDA
Serial Data (SDA) is a bidirectional pin used to transfer serial data into and out of the device. It has an open drain
output and may be wire OR’ed with other open drain or open collector outputs.
SCL
The Serial Clock (SCL) input is used to clock all serial data into and out of the device. The input buffer on this pin is
always active (not gated).
IRQ/F_OUT Interrupt Output/Frequency Output is a multi-functional pin that can be used as interrupt or frequency output pin. It
is an open drain output. The function is set via the configuration register.
V_BAT
V_DD
NC
This input provides a backup supply voltage to the device. V_BAT supplies power to the device in the event that the
V_DD supply fails. This pin should be tied to ground if not used.
Power Supply.
No Internal Connection.
2
FN6206.10
December 16, 2010