X1228 Datasheet, PDF (1/31 Pages) Xicor Inc. – Real Time Clock/Calendar/CPU Supervisor with EEPROM

New Features
Repetitive Alarms &
Temperature Compensation
4K (512 x 8)
X1228
2-Wire^™ RTC
Real Time Clock/Calendar/CPU Supervisor with EEPROM
FEATURES
• Real Time Clock/Calendar
— Tracks time in Hours, Minutes, and Seconds
— Day of the Week, Day, Month, and Year
• 2 Polled Alarms (Non-volatile)
— Settable on the Second, Minute, Hour, Day of the
Week, Day, or Month
— Repeat Mode (periodic interrupts)
• Oscillator Compensation on chip
— Internal feedback resistor and compensation
capacitors
— 64 position Digitally Controlled Trim Capacitor
— 6 digital frequency adjustment settings to
±30ppm
• CPU Supervisor Functions
— Power On Reset, Low Voltage Sense
— Watchdog Timer (SW Selectable: 0.25s, 0.75s,
1.75s, off)
• Battery Switch or Super Cap Input
• 512 x 8 Bits of EEPROM
— 64-Byte Page Write Mode
— 8 modes of Block Lock™ Protection
— Single Byte Write Capability
• High Reliability
— Data Retention: 100 years
— Endurance: 100,000 cycles per byte
• 2-Wire™ Interface interoperable with I2C*
— 400kHz data transfer rate
• Frequency Output (SW Selectable: Off, 1Hz,
4096Hz, or 32.768kHz)
• Low Power CMOS
— 1.25µA Operating Current (Typical)
• Small Package Options
— 14-Lead SOIC and 14-Lead TSSOP
APPLICATIONS
• Utility Meters
• HVAC Equipment
• Audio / Video Components
• Set Top Box / Television
• Modems
• Network Routers, Hubs, Switches, Bridges
• Cellular Infrastructure Equipment
• Fixed Broadband Wireless Equipment
• Pagers / PDA
• POS Equipment
• Test Meters / Fixtures
• Office Automation (Copiers, Fax)
• Home Appliances
• Computer Products
• Other Industrial / Medical / Automotive
BLOCK DIAGRAM
X1
32.768kHz
X2
PHZ/IRQ
Select
SCL
SDA
Serial
Interface
Decoder
RESET
Control
Decode
Logic
8
OSC Compensation
Oscillator
Frequency 1Hz
Divider
Timer
Calendar
Logic
Time
Keeping
Registers
(SRAM)
Control/
Registers
(EEPROM)
Status
Registers
(SRAM)
Alarm
Watchdog
Timer
Low Voltage
Reset
Compare
Alarm Regs
(EEPROM)
4K
EEPROM
ARRAY
Battery
Switch
Circuitry
V_CC
V_BACK
*I2C is a Trademark of Philips.
REV 1.3 3/24/04
www.xicor.com
Characteristics subject to change without notice. 1 of 31