New Features
Repetitive Alarms &
Temperature Compensation
4K (512 x 8)
2-Wire™ RTC
X1228
Real Time Clock/Calendar/CPU Supervisor with EEPROM
• 2-Wire™ Interface interoperable with I2C*
—433kHz data transfer rate
• Frequency Output (SW Selectable: Off, 1Hz,
4396Hz, or ±2.768kHz)
• Low Power CMOS
—1.25µA Operating Current (Typical)
• Small Package Options
FEATURES
• Real Time Clock/Calendar
—Tracks time in Hours, Minutes, and Seconds
—Day of the Week, Day, Month, andYear
• 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
—14-Lead SOIC and 14-LeadTSSOP
APPLICATIONS
• Utility Meters
—64 position Digitally Controlled Trim Capacitor
—6 digital frequency adjustment settings to
±±3ppm
• 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
• CPU Supervisor Functions
—Power On Reset, Low Voltage Sense
—Watchdog Timer (SW Selectable: 3.25s, 3.75s,
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: 133 years
—Endurance: 133,333 cycles per byte
• Other Industrial / Medical / Automotive
BLOCK DIAGRAM
OSC Compensation
X1
X2
Select
Timer
Calendar
Logic
Battery
Switch
Circuitry
Time
Keeping
Registers
V
V
CC
Frequency
Divider
1Hz
Oscillator
32.768kHz
BACK
(SRAM)
PHZ/IRQ
Status
Control/
Control
Decode
Logic
Compare
Serial
Interface
Decoder
Registers
SCL
SDA
Registers
Alarm
(EEPROM)
(SRAM)
Alarm Regs
(EEPROM)
8
4K
EEPROM
ARRAY
Watchdog
Timer
Low Voltage
Reset
RESET
*I2C is a Trademark of Philips.
REV 1.3 3/24/04
Characteristics subject to change without notice. 1 of 31
www.xicor.com
XICOR [ XICOR INC. ]
