ISL12026IBZ Intersil, ISL12026IBZ Datasheet - Page 13

• Manufacturer Part Number: ISL12026IBZ
• Description: IC RTC/CALENDAR EEPROM 8-SOIC
• Manufacturer: Intersil
• Type: Clock/Calendar/EEPROMr

Specifications of ISL12026IBZ

• 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-SOIC (3.9mm Width)
• Clock Format: HH
• Clock Ic Type: RTC
• Interface Type: I2C, Serial
• Memory Configuration: 512 X 8
• Supply Voltage Range: 2.7V To 5.5V
• Digital Ic Case Style: SOIC
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Writing to the Alarm Registers
The Alarm Registers are non-volatile but require special
attention to insure a proper non-volatile write takes place.
Specifically, byte writes to individual registers are good for all
but registers 0006h and 0000Eh, which are the DWA0 and
DWA1 registers, respectively. Those registers will require a
special page write for non-volatile storage. The recommended
page write sequences are as follows:
2. Interrupt Mode (or “Pulsed Interrupt Mode” or PIM) is
1. 16-byte page writes: The best way to write or update the
2. Other non-volatile writes: It is possible to do writes of
to trigger alarms. The IRQ/F
either alarm, and will need to be cleared to enable
triggering by a subsequent alarm. Polling the SR will
reveal which alarm has been set.
enabled by setting the AL0E or AL1E bit to “1” the IM bit
to “1”, and disabling the frequency output. If both AL0E
and AL1E bits are set to "1", then both AL0E and AL1E
PIM alarms will function. The IRQ/F
be pulsed each time each of the alarms occurs. This
means that once the interrupt mode alarm is set, it will
continue to alarm for each occurring match of the alarm
and present time. This mode is convenient for hourly or
daily hardware interrupts in microcontroller applications
such as security cameras or utility meter reading.
Interrupt Mode CANNOT be used for general periodic
alarms, however, since a specific time period cannot be
programmed for interrupt, only matches to a specific time
of day. The interrupt mode is only stopped by disabling
the IM bit or the Alarm Enable bits.
Alarm Registers is to perform a 16-byte write beginning at
address 0001h (MNA0) and wrapping around and ending
at address 0000h (SCA0). This will insure that
non-volatile storage takes place. This means that the
code must be designed so that the Alarm0 data is written
starting with Minutes register, and then all the Alarm1
data, with the last byte being the Alarm0 Seconds (the
page ends at the Alarm1 Y2k register and then wraps
around to address 0000h).
Alternatively, the 16-byte page write could start with
address 0009h, wrap around and finish with address
0008h. Note that any page write ending at address
0007h or 000Fh (the highest byte in each Alarm) will not
trigger a non-volatile write, so wrapping around or
overlapping to the following Alarm's Seconds register is
advised.
less than an entire page, but the final byte must always
be addresses 0000h through 0004h or 0008h though
000Ch to trigger a non-volatile write. Writing to those
blocks of 5 bytes sequentially, or individually, will trigger a
non-volatile write. If the DWA0 or DWA1 registers need to
be set, then enough bytes will need to be written to
overlap with the other Alarm register and trigger the
non-volatile write. For Example, if the DWA0 register is
being set, then the code can start with a multiple byte
write beginning at address 0006h, and then write 3 bytes
ending with the SCA1 register as follows:
13
OUT
output will be set by
OUT
output will now
ISL12026, ISL12026A
If the Alarm1 is used, SCA1 would need to have the correct
data written.
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
an Intersil RTC device for up to 10 years. Another option is
to use a SuperCap for applications where V
for up to a month. See “Application Section” on page 19 for
more information.
There are two options for setting the change-over conditions
from V
register controls this operation:
•
•
Note that the I
battery backup. That function is controlled by the SBIB bit.
That operation is covered after the power control section.
OPTION 1- STANDARD POWER CONTROL MODE
(ISL12026A DEFAULT)
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
To transition from the V
following conditions must be met:
• Battery Backup Mode (V
(V
- Condition 1:
- Condition 2:
Addr
0006h DWA0
0007h Y2K0
0008h SCA1
Option 1 - Standard Mode (ISL12026A Default)
Option 2 - Legacy Mode (ISL12026 Default)
BAT
V
where V
V
where V
DD
DD
DD
)
< V
< V
to Battery backup mode. The BSW bit in the PWR
DD
Name
BATHYS
TRIP
BAT
TRIP
2
DD
supply is shut off.
C bus may or may not be operational during
- V
≈ 2.2V
drops below V
BATHYS
≈ 50mV
DD
to V
BAT
DD
) to Normal Mode (V
BAT
) to Battery Backup Mode
TRIP
mode, both of the
DD
or V
and a V
BAT
DD
, whichever is
November 30, 2010
is interrupted
BAT
DD
input.
)
FN8231.9