ISL12020MIRZ Intersil, ISL12020MIRZ Datasheet - Page 10

• Manufacturer Part Number: ISL12020MIRZ
• Description: IC RTC/CALENDAR TEMP SNSR 20-DFN
• Manufacturer: Intersil
• Type: Clock/Calendarr

Specifications of ISL12020MIRZ

• Memory Size: 1K (128 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: 20-DFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Typical Performance Curves
General Description
The ISL12020M device is a low power real time clock
(RTC) with embedded temperature sensor and crystal.
It contains crystal frequency compensation circuitry
over the operating temperature range good to ±5ppm
accuracy. It also contains a clock/calendar with Daylight
Savings Time (DST) adjustment, power fail and low
battery monitors, brownout indicator, 1 periodic or
polled alarm, intelligent battery-backup switching and
128 Bytes of battery-backed user SRAM.
The oscillator uses an internal 32.768kHz crystal. The
real time clock tracks time with separate registers for
hours, minutes and seconds. The device has calendar
registers for date, month, year and day of the week. The
calendar is accurate through 2099, with automatic leap
year correction. In addition, both the ISL12020M could
be programmed for automatic Daylight Savings Time
(DST) adjustment by entering local DST information.
The ISL12020M’s alarm can be set to any clock/calendar
value for a match. For example, every minute, every
Tuesday or at 5:23 AM on March 21. The alarm status is
available by checking the Status Register, or the device
can be configured to provide a hardware interrupt via the
IRQ/F
allowing a periodic interrupt every minute, every hour,
every day, etc.
The device also offers a backup power input pin. This
V
Super Capacitor with automatic switchover from V
V
to 5.5V and the clock/calendar portion of the device
remains fully operational in battery-backup mode down
to 1.8V (Standby Mode). The V
and reported against preselected levels. The first report
is registered when the V
nominal level, the second level is set for 75%. Battery
levels are stored in PWR_VBAT registers.
The ISL12020M offers a “Brownout” alarm once the V
falls below a pre-selected trip level. This allows system
Micro to save vital information to memory before
BAT
BAT
FIGURE 10. I
110
100
. The ISL12020M device is specified for V
90
80
70
60
50
40
pin allows the device to be backed up by battery or
OUT
-40
pin. There is a repeat mode for the alarm
-20
DD
V
V
DD
BAT
with TSE = 1 vs TEMPERATURE
= 5.5V
= 2.7V
TEMPERATURE (°C)
0
BAT
10
level falls below 85% of
20
BAT
level is monitored
40
V
DD
60
DD
= 3.3V
= 2.7V
ISL12020M
80
DD
Temperature is +25°C unless otherwise specified. (Continued)
DD
to
complete power loss. There are six V
be selected for initiation of the Brownout alarm.
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 ISL12020M for up to 10 years.
Another option is to use a Super Capacitor for
applications where V
See the “Application Section” on page 27 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 ISL12020M 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.
DD
DD
DD
DD
FIGURE 11. OSCILLATOR CHANGE vs TEMPERATURE
BAT
< V
< V
> V
> V
-20
-40
-60
-80
80
60
40
20
)
BATHYS
TRIP
BATHYS
TRIPHYS
BAT
TRIP
BAT
TRIP
0
-40
DD
- V
+ V
≈ 2.2V
+ V
)
AT DIFFERENT AGING SETTINGS (IATR)
(BETA SET FOR 1ppm STEPS)
BATHYS
≈ 50mV
≈ 50mV
BATHYS
-20
≈ 30mV
TRIPHYS
DD
DD
DD
) to Battery-Backup Mode
TEMPERATURE (°C)
is interrupted for up to a month.
0
to V
BAT
20
BAT
62.5ppm
-61.5ppm
-31ppm
mode, both of the
32ppm
0ppm
) to Normal
DD
DD
40
levels that could
and a V
February 11, 2010
BAT
60
BAT
to V
FN6667.4
80
DD