Low Power RTC with VDD 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 VDD to battery power, and also from battery to VDD power.

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 FOUT 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 VBAT = 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 VDD to VBAT, and Last VBAT to VDD

• 128 Bytes Battery-Backed User SRAM

• I2C 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