ISL12022MIBZ-T Intersil, ISL12022MIBZ-T Datasheet - Page 11

• Manufacturer Part Number: ISL12022MIBZ-T
• Description: IC RTC/CALENDAR TEMP SENS 20SOIC
• Manufacturer: Intersil
• Type: Clock/Calendarr

Specifications of ISL12022MIBZ-T

• Memory Size: 128B
• 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: 20-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ISL12022MIBZ-TCT

Functional Description
Power Control Operation
The power control circuit accepts a V
input. 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 ISL12022M for up to 10 years.
Another option is to use a supercapacitor for applications
where V
“Application Section” on page 26 for more information.
Normal Mode (V
(V
To transition from the V
following conditions must be met:
Condition 1:
V
where V
Condition 2:
V
where V
Battery Backup Mode (V
Mode (V
The ISL12022M device will switch from the V
mode when one of the following conditions occurs:
Condition 1:
V
where V
Condition 2:
V
where V
These power control situations are illustrated in
Figures 12 and 13.
The I
reduce power consumption. Aside from this, all RTC
functions are operational during battery backup mode.
Except for SCL and SDA, all the inputs and outputs of
the ISL12022M are active during battery backup mode
unless disabled via the control register.
FIGURE 12. BATTERY SWITCHOVER WHEN
DD
DD
DD
DD
V
BAT
V
V
TRIP
V
BAT
BAT
< V
< V
> V
> V
2
DD
C bus is deactivated in battery backup mode to
)
DD
BATHYS
TRIP
BATHYS
TRIPHYS
- V
BAT
TRIP
BAT
TRIP
DD
BATHYS
is interrupted for up to a month. See the
V
- V
+ V
≈ 2.2V
+ V
BAT
)
BATHYS
≈ 50mV
≈ 50mV
BATHYS
≈ 30mV
TRIPHYS
< V
DD
BATTERY BACKUP
TRIP
DD
) to Battery Backup Mode
11
MODE
to V
BAT
BAT
mode, both of the
) to Normal
V
DD
BAT
and a V
+ V
BATHYS
BAT
BAT
2.2V
1.8V
to V
ISL12022M
DD
FIGURE 13. BATTERY SWITCHOVER WHEN V
The device Time Stamps the switchover from V
V
and t
power-down sequences occur before the status is read,
the earliest V
the most recent V
Temperature conversion and compensation can be
enabled in battery backup mode. Bit BTSE in the BETA
register controls this operation, as described in “BETA
Register (BETA)” on page 19.
Power Failure Detection
The ISL12022M provides a Real Time Clock Failure Bit
(RTCF) to detect total power failure. It allows users to
determine if the device has powered up after having lost
all power to the device (both V
Brownout Detection
The ISL12022M monitors the V
provides warning if the V
levels. There are six (6) levels that can be selected for
the trip level. These values are 85% below popular V
levels. The LVDD bit in the Status Register will be set to
“1” when brownout is detected. Note that the I
bus remains active unless the Battery V
reached.
Battery Level Monitor
The ISL12022M has a built-in warning feature once the
backup battery level drops first to 85% and then to 75%
of the battery’s nominal V
voltage drops to between 85% and 75%, the LBAT85 bit
is set in the status register. When the level drops below
75%, both LBAT85 and LBAT75 bits are set in the status
register.
The battery level monitor is not functional in battery
backup mode. In order to read the monitor bits after
powering up V
by setting the TSE bit to "1" (BETA register), and then
read the bits.
There is a Battery Time Stamp Function available. Once
the V
battery, the RTC time/date are written into the TSV2B
register. This information can be read from the TSV2B
registers to discover the point in time of the V
power-down. If there are multiple power-down cycles
before reading these registers, the first values stored in
BAT
V
V
V
TRIP
DD
BAT
SB2V
DD
and V
is low enough to enable switchover to the
registers respectively. If multiple V
V
BAT
TRIP
V
DD
TRIP
DD
to V
to V
, instigate a battery level measurement
BAT
DD
BATTERY BACKUP
BAT
to V
, and the time is stored in t
DD
power-down time is stored and
MODE
BAT
DD
level drops below prescribed
level. When the battery
time is stored.
DD
DD
and V
level continuously and
V
TRIP
TRIP
BAT
+ V
).
TRIPHYS
levels are
BAT
DD
DD
2
June 4, 2010
3.0V
2.2V
DD
C serial
>
FN6668.7
SV2B
to
DD