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) with an embedded temperature sensor and
crystal. Device 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 over the full -40°C to +85°C temperature
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.
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 function records the time and date of
switchover from VDD to VBAT power, and also from VBAT
to VDD power.
• Embedded 32.768kHz Quartz Crystal in the Package
• 20 Ld DFN Package (for SOIC version, refer to the
• On-chip Oscillator Temperature Compensation
• 10-bit Digital Temperature Sensor Output
• 15 Selectable Frequency Outputs
• Interrupt for Alarm or 15 Selectable Frequency
• Automatic Backup to Battery or Supercapacitor
• VDD and Battery Status Monitors
• Battery Reseal™ Function to Extend Battery Shelf
• Power Status Brownout Monitor
• Time Stamp for Battery Switchover
• 128 Bytes Battery-Backed User SRAM
• RoHS Compliant
Applications*(see page 31)
• Utility Meters
• POS Equipment
• Printers and Copiers
• Digital Cameras
Typical Application Circuit
8 GND IRQ/FOUT 13
0.1µF R1 R2 R3
10k 10k 10k
OSCILLATOR ERROR vs TEMPERATURE
VBAT = 5.5V
VDD = 2.7V
VDD = 3.3V
February 11, 2010
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
I2C Bus™ is a trademark owned by NXP Semiconductors Netherlands, B.V.
Copyright Intersil Americas Inc. 2008, 2009, 2010. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.