2Kb SPI EEPROM with PIO, RTC, Reset, Battery Monitor, and Watchdog

The DS28DG02 combines 2Kb (256 x 8) EEPROM with 12 PIO lines, a real-time clock (RTC) and calendar with alarm function, a CPU reset monitor, a battery monitor, and a watchdog. Communication with the device is accomplished with an industry-standard SPI™ interface. The user EEPROM is organized as four blocks of 64 bytes each with single-byte and up to 16-byte page write capability. Additional registers provide access to PIOs and to setup functions. Individual PIO lines can be configured as inputs or outputs. The power-on state of PIOs programmed as outputs is stored in nonvolatile (NV) memory. All PIOs may be reconfigured by the user through the serial interface. The RTC/calendar operates in the 12/24-hour format and automatically corrects for leap years. Battery monitor threshold and watchdog timeout are user-programmable through NV registers. The reset monitor generates a reset to the CPU if the voltage at the VCC pin falls below the factory-set limit. The reset output includes a debounce circuit for manual pushbutton reset.

Applications

* Asset-Tracking Systems * Broadband Access Network Equipment * Holter Heart Monitors * Home Lighting Control Systems * Patient-Monitoring Systems * RAID Systems * Servers * Wireless Base Stations

* 2Kb (256 x 8) EEPROM Organized in Four 64-Byte Blocks

* Single Byte and Up to 16-Byte EEPROM Write Sequences

* EEPROM Write-Protect Control Pin Protects 1, 2, or All 4 Blocks

* Endurance 200k Cycles per Page at +25°C; 10ms (max) EEPROM Write Cycle

* SPI Serial Interface Supporting Modes (0,0) and (1,1) at Up to 2MHz Clock Frequency

* 12 PIO Lines with LED Drive Capability

* Each PIO is Configured to Input or Output, Open-Drain/Push-Pull on Startup by Stored Value

* All PIOs are Reconfigurable After Startup

* RTC/Calendar/Alarm with BCD Format and Leap-Year Compensation

* RTC Controlled Through 32.768kHz, 12.5pF Crystal or External TCXO

* CPU Reset Through Fast-Response Precision VCC Monitor with Hysteresis or Pushbutton

* Battery Monitor 2.5V, 2.25V, 2.0V, 1.75V, -5%

* Watchdog Timer 1.6s, 0.8s, 0.4s, 0.2s (typ)

* Unique Factory-Programmed 64-Bit Device Registration Number

* Operating Range: 2.2V to 5.25V, -40°C to +85°C

* ±4kV IEC 1000-4-2 ESD Protection Level (Except Crystal Pins)

* Available in 28-Lead, 4.4mm TSSOP or 36-Lead 6mm × 6mm QFN Package