ISL12024IRTCZ-T Intersil, ISL12024IRTCZ-T Datasheet - Page 14

• Manufacturer Part Number: ISL12024IRTCZ-T
• Description: IC RTC/CALENDER 64BIT 8-TDFN
• Manufacturer: Intersil
• Type: Clock/Calendar/EEPROMr

Specifications of ISL12024IRTCZ-T

• Memory Size: 4K (512 x 8)
• Time Format: HH:MM:SS (12/24 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-TDFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Note that the I
battery backup, which is controlled by the SBIB bit. See
“Backup Battery Operation” on page 22 for information.
The V
circuit to protect from incorrect serial bus writes after a
brownout situation. This circuit disables the serial bus for
about 90ms following the power-up. To trigger the delay, the
V
approximately 1.0V (limit of active circuit operation). After
that, the power-up ramp must be slower than 0.25V/ms to
trigger the delay. To be safe, serial interface software may
need to consider the 90ms delay in all power-up routines.
OPTION 1 - STANDARD (POWER CONTROL) MODE
In the Standard Mode, the supply will switch over to the
battery when V
lower. In this mode, accidental operation from the battery is
prevented since the battery backup input will only be used
when the V
To select Option 1, BSW bit in the Power Register must be
set to “BSW = 0”. A description of power switchover follows:
Standard Mode Power Switchover
• Normal Operating Mode (V
• Battery Backup Mode (V
There are two discrete situations that are possible when
using Standard Mode: V BAT < V TRIP and V BAT > V TRIP .
These two power control situations are illustrated in
Figures 9 and 10.
DD
(V
To transition from the V
following conditions must be met:
- Condition 1:
- Condition 2:
The ISL12024IRTCZ device will switch from the V
V
- Condition 1:
- Condition 2:
DD
BAT
V
where V
V
where V
V
where V
V
where V
must drop below the battery trip point yet stay above
DD
DD
DD
DD
DD
mode when one of the following conditions occurs:
)
/V
< V
< V
> V
> V
BAT
DD
BATHYS
TRIP
BATHYS
TRIPHYS
BAT
TRIP
BAT
TRIP
2
supply is shut off.
DD
C bus may or may not be operational during
power circuit also contains a glitch detection
- V
+ V
≈ 2.2V
drops below V
+ V
BATHYS
BATHYS
≈ 50mV
≈ 50mV
TRIPHYS
≈ 30mV
DD
BAT
14
to V
DD
) to Normal Mode (V
TRIP
) to Battery Backup Mode
BAT
or V
mode, both of the
BAT
, whichever is
DD
BAT
ISL12024IRTCZ
)
to
OPTION 2 - LEGACY (POWER CONTROL) MODE
(DEFAULT)
The Legacy Mode follows conditions set in X1226 products.
In this mode, switching from V
comparing the voltages and the device operates from
whichever is the higher voltage. Care should be taken when
changing from Normal to Legacy Mode. If the V
higher than V
and unless the battery is disconnected or the voltage
decreases, the device will no longer operate from V
To select Option 2, the BSW bit in the Power Register must
be set to “BSW = 1”.
• Normal Mode (V
• Battery Backup Mode (V
The Legacy Mode power control conditions are illustrated in
Figure 11.
To transition from the V
conditions must be met:
V
The device will switch from the V
the following condition occurs:
V
FIGURE 10. BATTERY SWITCHOVER WHEN V
FIGURE 9. BATTERY SWITCHOVER WHEN V
V
V
DD
DD
V
V
V
TRIP
V
TRIP
BAT
BAT
DD
DD
V
< V
> V
BAT
BAT
BAT
- V
V
DD
BATHYS
TRIP
+V
- V
, then the device will enter battery backup
BATHYS
BATHYS
DD
) to Battery Backup Mode (V
BATTERY BACKUP
BATTERY BACKUP
DD
BAT
MODE
to V
DD
MODE
) to Normal Mode (V
to V
BAT
BAT
BAT
mode, the following
to V
is simply done by
V
TRIP
DD
V
BAT
BAT
BAT
BAT
+ V
mode when
+ V
August 8, 2008
TRIPHYS
< V
BAT
DD
voltage is
> V
DD
BATHYS
3.0V
2.2V
FN6749.0
2.2V
1.8V
TRIP
.
TRIP
)
)