X1205 Datasheet, PDF (1/22 Pages) Xicor Inc. – Real Time Clock/Calendar

Preliminary Information
New Features
Repetitive Alarms &
Temperature Compensation
X1205
Real Time Clock/Calendar
2-Wire^™ RTC
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
• Battery Switch or Super Cap Input
• 2-Wire™ Interface interoperable with I2C*
—400kHz data transfer rate
• Low Power CMOS
—1.25µA Operating Current (Typical)
• Small Package Options
—8-Lead SOIC and 8-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
DESCRIPTION
The X1205 device is a Real Time Clock with clock/
calendar, two polled alarms, oscillator compensation,
and battery backup switch.
The oscillator uses an external, low-cost 32.768kHz
crystal. All compensation and trim components are
integrated on the chip. This eliminates several external
discrete components and a trim capacitor, saving
board area and component cost.
The Real-Time Clock keeps track of time with separate
registers for Hours, Minutes, and Seconds. The
Calendar has separate registers for Date, Month, Year
and Day-of-week. The calendar is correct through
2099, with automatic leap year correction.
BLOCK DIAGRAM
OSC
Compensation
X1
32.768kHz
X2
Oscillator
Frequency 1Hz
Divider
Timer
Calendar
Logic
Time
Keeping
Registers
(SRAM)
SCL
SDA
Serial
Interface
Decoder
IRQ
Control
Decode
Logic
8
*I2C is a Trademark of Philips.
REV 1.0.9 8/29/02
Control
Registers
(EEPROM)
Status
Registers
(SRAM)
Interrupt Enable
Alarm
www.xicor.com
Alarm
Compare
Alarm Regs
(EEPROM)
Characteristics subject to change without notice. 1 of 22