1
®
FN6451.0
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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ISL12021
Real Time Clock with On Chip Temp Compensation ±5ppm
Low Power RTC with V
DD
Battery Backed
SRAM and Embedded Temp
Compensation ±5ppm with Auto Day Light
Saving
The ISL12021 device is a low power real time clock with an
embedded Temp sensor for oscillator compensation,
clock/calendar, power fail, low battery monitor, brown out
indicator, single periodic or polled alarms, intelligent battery
backup switching and 128 bytes of battery-backed user
SRAM.
The oscillator uses an external, low-cost 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.
Daylight Savings time adjustment is done automatically,
using parameters entered by the user. Power fail and battery
monitors offer user-selectable trip levels. A time stamp
function records the time and date of switchover from V
DD
to
battery power, and also from battery to V
DD
power.
Pinout
ISL12021
(14 LD TSSOP)
TOP VIEW
Features
• Real Time Clock/Calendar
- Tracks Time in Hours, Minutes and Seconds
- Day of the Week, Day, Month and Year
• On-chip Oscillator Compensation Over the Operating
Temp Range
- ±5ppm over -20°C to +70°C
• Day Light Saving Time
- Customer Programmable
• Separate F
OUT
pin
- 15 Selectable Frequency Outputs
• 1 Alarm
- Settable to the Second, Minute, Hour, Day of the Week,
Day, or Month
- Single Event or Pulse Interrupt Mode
- Dedicated IRQ
output pin
• Automatic Backup to Battery or Super Cap
- Operation to V
BAT
= 1.8V
- 1.0µA Battery Supply Current
• Battery Status Monitor, 2 Levels, Selectable by Customer
to:
- Seven Selectable Voltages for Each Level
• Power status Brown Out Monitor
- Six selectable trip level, from 4.675V to 2.295V
- Separate Low Voltage LVRST
pin
• Time Stamp during Power to Battery and Battery to Power
Cross Over
- Time Stamp. First V
DD
to V
BAT
, and Last V
BAT
to V
DD
• 128 Bytes Battery-Backed User SRAM
•I
2
C Interface
- 400kHz Clock Frequency
• 14 Ld TSSOP package
• Pb-Free Plus Anneal Available (RoHS Compliant)
Applications
• Utility Meters
• POS Equipment
• Medical Application
• Security Related Application
• Vending Machine
• White Goods
V
DD
IRQ
SCL
SDA
X1
X2
V
BAT
2
3
4
5
13
12
11
GND
F
OUT
LVRST
NC
NC
NC
NC
1
6
7
8
9
10
14
Data Sheet March 30, 2007