
3
FN8085.8
September 12, 2008
Pin Descriptions
PIN
NUMBER SYMBOL
DESCRIPTION
1
X1
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. X1 can also be driven directly from a 32.768kHz source.
2
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.
3
VBAT
This input provides a backup supply voltage to the device. VBAT supplies power to the device in the event that the VDD supply
fails. This pin should be tied to ground if not used.
4
GND
Ground
5
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.
6
SCL
The Serial Clock (SCL) input is used to clock all serial data into and out of the device.
7IRQ/FOUT 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.
8
VDD
Power supply
ISL1208