FM3808 Datasheet | Ramtron

Features 256K bit Ferroelectric Nonvolatile RAM - Organized as 32,752 x 8 bits - High Endurance 100 Billion (1011) Read/Writes - 10 year Data Retention - No Delay™ Writes - 70 ns Access Time/ 130 ns Cycle Time - Built-in Low VDD Protection Real-Time Clock/Calendar Function - Clock Registers in Top 16 bytes of Address Space - Backup Power from External Capacitor or Battery - Tracks Seconds through Centuries in BCD Format - Tracks Leap Years through 2099 - Runs from a 32.768 k Hz Timekeeping Crystal System Supervisor Function - Programmable Clock/Calendar Alarm - Programmable Watchdog Timer - Power Supply Monitor - Interrupt Output - Programmable active high/low - Control Settings Inherently Nonvolatile - Generates either Processor Reset or Interrupt Low Power Operation - 5V Operation for Memory and Clock Interface - Backup Voltage as low as 2.5V - 25 m A IDD Active Current - 1 µA IBAK Clock Backup Current Description The FM3808 bines a 256Kb FRAM array with a real-time clock and a system supervisor function. An external 32.768 k Hz crystal drives the timekeeping function. It maintains time and date settings in the absence of system power through the user’s choice of backup power source - either a capacitor or a battery. In either case data in the memory array does not depend on the backup source, it remains nonvolatile in FRAM. In addition to timekeeping, the FM3808 includes a system supervisor to manage low VDD power conditions and a watchdog timer function. A programmable interrupt output pin allows the user to select the supervisor functions and the polarity of the signal. Pin Configuration A11 A9 A8 A13 VBAK...