ISL12008IB8Z-T Intersil, ISL12008IB8Z-T Datasheet - Page 7

• Manufacturer Part Number: ISL12008IB8Z-T
• Description: IC RTC I2C LO-POWER 8-SOIC
• Manufacturer: Intersil
• Type: Clock/Calendarr

Specifications of ISL12008IB8Z-T

• Time Format: HH:MM:SS (24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -

the crystal timing accuracy over-temperature either during
manufacturing or with an external temperature sensor and
microcontroller for active compensation (see Figure 6).
V
This input provides a backup supply voltage to the device.
V
supply fails. This pin can be connected to a battery, a super
capacitor or tied to ground if not used.
FT/OUT (512Hz Frequency Output/Logic Output)
This dual function pin can be used as a 512Hz frequency
output pin for on-chip crystal compensation or a simple
digital output control via I
via the OUT and FT control bits of the control/status register
(address 07h). This pin is an open drain output requires the
use of a pull-up resistor.
Serial Clock (SCL)
The 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). It is disabled when the backup power supply on the
V
Serial Data (SDA)
SDA is a bidirectional pin used to transfer data into and out
of the device. It has an open drain output and may be ORed
with other open drain or open collector outputs. The input
buffer is always active (not gated) in normal mode.
An open drain output requires the use of a pull-up resistor.
The output circuitry controls the fall time of the output signal
with the use of a slope controlled pull-down. The circuit is
designed for 400kHz I
backup power supply on the VBAT pin is activated.
V
Chip power supply and ground pins. The device will operate
with a power supply from 2.7V to 5.5VDC. A 0.1µF
decoupling capacitor is recommended on the V
ground.
Functional Description
Power Control Operation
The power control circuit accepts a V
Many types of batteries can be used with Intersil RTC
products. For example, 3.0V or 3.6V Lithium batteries are
appropriate, and battery sizes are available that can power
the ISL12008 for up to 10 years. Another option is to use a
super capacitor for applications where V
BAT
BAT
BAT
DD
FIGURE 6. RECOMMENDED CRYSTAL CONNECTION
, GND
supplies power to the device in the event that the V
pin is activated to minimize power consumption.
2
C bus speeds. It is disabled when the
2
C. The FT/OUT mode is selected
7
X1
X2
DD
DD
and a V
is interrupted for
DD
BAT
pin to
input.
DD
ISL12008
up to a month. See “Application Section” on page 16 for
more information.
Normal Mode (V
(V
To transition from the V
following conditions must be met:
Condition 1:
Condition 2:
Battery Backup Mode (V
(V
The ISL12008 device will switch from the V
when one of the following conditions occurs:
Condition 1:
Condition 2:
These power control situations are illustrated in Figures 7
and 8.
BAT
DD
V
where V
V
where V
V
where V
V
where V
FIGURE 7. BATTERY SWITCHOVER WHEN V
FIGURE 8. BATTERY SWITCHOVER WHEN V
V
V
V
V
V
DD
DD
DD
DD
V
TRIP
TRIP
BAT
DD
BAT
)
V
DD
BAT
)
< V
< V
> V
> V
- V
BATHYS
TRIP
BATHYS
TRIPHYS
BAT
TRIP
BAT
TRIP
BATHYS
V
TRIP
- V
+ V
≈ 2.6V
+ V
BATHYS
DD
BATHYS
≈ 50mV
≈ 50mV
TRIPHYS
≈ 30mV
) to Battery Backup Mode
BATTERY BACKUP
DD
BATTERY BACKUP
to V
MODE
BAT
MODE
BAT
) to Normal Mode
mode, both of the
V
V
BAT
TRIP
BAT
BAT
BAT
September 26, 2008
+ V
to V
+ V
BATHYS
TRIPHYS
< V
> V
DD
3.0V
2.6V
2.6V
1.8V
TRIP
TRIP
FN6690.1
mode