Maker : Xicor
Part No. : X1227

  Datasheet PDF : X1227.pdf
  Cross Reference : X1227 Cross Reference
  Buy Component : X1227 Find Stock and Price

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Product Information

New Features Repetitive Alarms & Temperature Compensation 4K (512 x 8) X1227 APPLICATIONS • • • • • • • • • • • • • • • 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 • 4K 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 • Low Power CMOS — 1.25µA Operating Current (Typical) • Small Package Options — 8-Lead SOIC and 8-Lead TSSOP 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 X1227 device is a Real Time Clock with clock/ calendar, two polled alarms with integrated 512x8 EEPROM, oscillator compensation, CPU Supervisor (POR/LVS and WDT) 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. BLOCK DIAGRAM OSC Compensation X1 Timer Calendar Logic Time Keeping Registers (SRAM) Battery Switch Circuitry VCC VBACK 32.768kHz X2 Oscillator Frequency Divider 1Hz SCL SDA 8 RESET Watchdog Timer Low Voltage Reset Mask Serial Interface Decoder Control Decode Logic Control/ Registers (EEPROM) Status Registers (SRAM) Alarm Compare Alarm Regs (EEPROM) 4K EEPROM ARRAY *I2C is a Trademark of Philips. REV 1.1.20 1/13/03 www.xicor.com Characteristics subject to change without notice. 1 of 28 X1227 DESCRIPTION (continued) The Real-Time Clock keeps track of time with separate registers for Hours, Minutes, Seconds. The Calendar has separate registers for Date, Month, Year and Dayof-week. The calendar is correct through 2099, with automatic leap year correction. The powerful Dual Alarms can be set to any Clock/ Calendar value for a match. For instance, every minute, every Tuesday, or 5:23 AM on March 21. The alarms can be polled in the Status Register. There is a repeat mode for the alarms allowing a periodic interrupt. The X1227 device integrates CPU Supervisor functions and a Battery Switch. There is a Power-On Reset (RESET output) with typically 250 ms delay from power on. It will also assert RESET when Vcc goes below the specified threshold. The Vtrip threshold is user reprogrammable. There is a WatchDog Timer (WDT) with 3 selectable time-out periods (0.25s, 0.75s, 1.75s) and a disabled setting. The watchdog activates the RESET pin when it expires. The device offers a backup power input pin. This VBACK pin allows the device to be backed up by battery or SuperCap. The entire X1227 device is fully operational from 2.7 to 5.5 volts and the clock/calendar portion of the X1227 device remains fully operational down to 1.8 volts (Standby Mode). The X1227 device provides 4K bits of EEPROM with 8 modes of BlockLock™ control. The BlockLock allows a safe, secure memory for critical user ...

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