DATASHEET
ISL12020M
FN6667
Rev 6.00
January 9, 2015
Low Power RTC with Battery Backed SRAM, Integrated ±5ppm Temperature
Compensation and Auto Daylight Saving
The ISL12020M device is a low power Real Time Clock (RTC)
Features
with an embedded temperature sensor and crystal. Device
• Embedded 32.768kHz quartz crystal in the package
functions include oscillator compensation, clock/calendar,
power fail and low battery monitors, brownout indicator,
one-time, periodic or polled alarms, intelligent battery backup
switching, Battery Reseal™ function and 128 bytes of
battery-backed user SRAM. The device is offered in a
20 Ld DFN module that contains the RTC and an embedded
32.768kHz quartz crystal. The calibrated oscillator provides
less than ±5ppm drift across the 0°C to +85°C temperature
range.
• 20 Ld DFN package (for SOIC version, refer to the
ISL12022M)
• Calendar
• On-chip oscillator temperature compensation
• 10-bit digital temperature sensor output
• 15 selectable frequency outputs
• Interrupt for alarm or 15 selectable frequency outputs
• Automatic backup to battery or supercapacitor
The RTC tracks time with separate registers for hours, minutes
and seconds. The calendar registers track date, month, year
and day of the week and are accurate through 2099, with
automatic leap year correction.
• V and battery status monitors
DD
• Battery Reseal™ function to extend battery shelf life
• Power status brownout monitor
Daylight Savings time adjustment is done automatically, using
parameters entered by the user. Power fail and battery
monitors offer user-selectable trip levels. The time stamp
• Time stamp for battery switchover
function records the time and date of switchover from V to
• 128 Bytes battery-backed user SRAM
DD
V
power and also from V
BAT
to V power.
DD
2
BAT
• I C-Bus™
• RoHS compliant
Related Literature
• AN1549, “Addressing Power Issues in Real Time Clock
Applications”
Applications
• Utility meters
• AN1389, “Using Intersil’s High Accuracy Real Time Clock
Module”
• POS equipment
• Printers and copiers
• Digital cameras
1
2
3
4
5
6
7
8
9
X2
X1 20
X1 19
X2
X2
X1 18
X2
X1 17
3.3V
C1
X2
X1 16
SCHOTTKY DIODE
BAT54
NC
VBAT
GND
NC
NC 15
R2
R3
R1
0.1µF
VDD 14
IRQ/FOUT 13
SCL 12
SDA 11
10k 10k 10k
BATTERY
3.0V
C2
0.1µF
VDD
SCL
MCU
INTERFACE
10 NC
SDA
GND
ISL12020M
IRQ/FOUT
FIGURE 1. TYPICAL APPLICATION CIRCUIT
FN6667 Rev 6.00
January 9, 2015
Page 1 of 34