ISL12028_10 Datasheet, PDF (3/29 Pages) Intersil Corporation – Real Time Clock/Calendar with I2C Bus™ and EEPROM

ISL12028, ISL12028A
Pin Descriptions
PIN
NUMBER
1
SYMBOL
X1
2
X2
6
RESET
7
GND
8
SDA
9
SCL
12
IRQ/F_OUT
13
V_BAT
14
V_DD
3, 4, 5, 10,
NC
11
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.
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 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.
Ground.
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.
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).
Interrupt Output/Frequency Output is a multi-functional pin that can be used as interrupt or frequency output pin. The
function is set via the configuration register. It is a CMOS push-pull output and does not require a pull-up resistor.
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.
3
FN8233.8
August 9, 2010