ISL12020MIRZ Intersil, ISL12020MIRZ Datasheet - Page 17

• 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

Battery Voltage Trip Voltage Register
(PWR_VBAT)
This register controls the trip points for the two V
alarms, with levels set to approximately 85% and 75% of
the nominal battery level.
RESEAL BIT (RESEALB)
This is the Reseal bit for actively disconnecting V
from the internal circuitry. Setting this bit allows the
device to disconnect the battery and eliminate standby
current drain while the device is unused. Once V
powered up, this bit is reset and the V
connected to the internal circuitry.
The application for this bit involves placing the chip on a
board with a battery and testing the board. Once the
board is tested and ready to ship, it is desirable to
disconnect the battery to keep it fresh until the board or
unit is placed into final use. Setting RESEALB = “1”
initiates the battery disconnect, and after V
cycled down and up again, the RESEAL bit is cleared to
“0”.
BATTERY LEVEL MONITOR TRIP BITS
(VB85TP<2:0>)
Three bits select the first alarm (85% of Nominal V
level for the battery voltage monitor. There are total of
7 levels that could be selected for the first alarm. Any of
the of levels could be selected as the first alarm with no
reference as to nominal battery voltage level. See
Table 8.
BATTERY LEVEL MONITOR TRIP BITS
(VB75TP<2:0>)
Three bits select the second alarm (75% of Nominal
V
total of 7 levels that could be selected for the second
alarm. Any of the of levels could be selected as the
second alarm with no reference as to nominal Battery
voltage level. See Table 9.
ADDR 7
0Ah
BAT
VB85Tp2
) level for the battery voltage monitor. There are
0
0
0
0
1
1
1
D RESEALB VB85
TABLE 8. VB85T ALARM LEVEL
6
VB85Tp1
0
0
1
1
0
0
1
Tp2
5
TABLE 7.
17
VB85
Tp1
VB85Tp0
4
0
1
0
1
0
1
0
VB85
Tp0
3
BAT
BATTERY ALARM
VB75
Tp2
2
TRIP LEVEL
pin is then
DD
2.125
2.295
2.550
2.805
3.060
4.250
4.675
(V)
VB75
Tp1
power is
1
DD
BAT
BAT
ISL12020M
BAT
is
VB75
Tp0
pin
0
)
Initial AT and DT setting Register (ITRO)
These bits are used to trim the initial error (at room
temperature) of the crystal. Both Digital Trimming (DT)
and Analog Trimming (AT) methods are available. The
digital trimming uses clock pulse skipping and insertion
for frequency adjustment. Analog trimming uses load
capacitance adjustment to pull the oscillator frequency. A
range of +62.5ppm to -61.5ppm is possible with
combined digital and analog trimming.
Initial values for the ITR0 register are preset internally
and recalled to RAM registers on power-up. These
values can be overwritten by the user although
this is not suggested as the resulting temperature
compensation performance will be compromised.
Aging adjustment is normally a few ppm and can be
handled by writing to the IATR section.
AGING AND INITIAL TRIM DIGITAL TRIMMING
BITS (IDTR0<1:0>)
These bits allow ±30.5ppm initial trimming range for the
crystal frequency. This is meant to be a coarse
adjustment if the range needed is outside that of the
IATR control. See Table 10. The IDTR0 register should
only be changed while the TSE (Temp Sense Enable) bit
is “0”.
The ISL12020M has a preset Initial Digital Trimming
value corresponding to the crystal in the module. This
value is recalled on initial power-up and should never be
changed for best temperature compensation
performance, although the user may change this preset
value to adjust for aging or board mounting changes if so
desired.
TABLE 9. BATTERY LEVEL MONITOR TRIP BITS
VB75Tp2
IDTR01
0
0
0
0
1
1
1
0
0
1
1
TABLE 10. IDTR0 TRIMMING RANGE
(VB75TP<2:0>)
VB75Tp1
IDTR00
0
0
1
1
0
0
1
0
1
0
1
VB75Tp0
Default/Disabled
+30.5ppm
0ppm
-30.5ppm
0
1
0
1
0
1
0
TRIMMING RANGE
BATTERY ALARM
TRIP LEVEL
February 11, 2010
1.875
2.025
2.250
2.475
2.700
3.750
4.125
(V)
FN6667.4