ISL1209_06 Datasheet, PDF (2/24 Pages) Intersil Corporation – Low Power RTC with Battery Backed SRAM and Event Detection

Block Diagram
SDA
SCL
SDA
BUFFER
SCL
BUFFER
ISL1209
I²C
INTERFACE
CONTROL
LOGIC
X1
X2
V_DD
V_TRIP
V_BAT
CRYSTAL
OSCILLATOR
RTC
DIVIDER
POR
FREQUENCY
OUT
SWITCH
INTERNAL
SUPPLY
ALARM
EVIN
GND
Seconds
Minutes
Hours
Day of Week
Date
Month
Year
CONTROL
REGISTERS
USER
SRAM
IRQ/
F_OUT
EVDET
Pin Descriptions
PIN
NUMBER
1
2
3
4
5
6
7
8
9
SYMBOL
DESCRIPTION
X1
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.
X2
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. X2 should be left open when X1 is driven from external source.
V_BAT
GND
V_BAT. 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.
Ground.
EVIN
Event Input (EVIN). The EVIN is an input pin that is used to detect an externally monitored event. When a high signal
is present at the EVIN pin an “event” is detected.
EVDET Event Detect Output, active when EVIN is triggered. Open drain output.
SDA
Serial Data (SDA). 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
Serial Clock (SCL). The SCL input is used to clock all serial data into and out of the device.
IRQ/F_OUT Interrupt Output IRQ, /Frequency Output F_OUT. Multi-functional pin that can be used as interrupt or frequency
output pin. The function is set via the configuration register.
10
V_DD
V_DD. Power supply.
2
FN6109.4
October 17, 2006