FM4005 Datasheet, PDF (1/23 Pages) Formosa MS – Chip Silicon Rectifier - Glass passivated type

Pre-Production
FM4005
Integrated Processor Companion
Features
High Integration Device Replaces Multiple Parts
• Real-time Clock (RTC)
• Low Voltage Reset
• Watchdog Timer
• Early Power-Fail Warning/NMI
• Two 16-bit Event Counters
• Serial Number with Write-lock for Security
Real-Time Clock/Calendar
• Backup Current under 1 µA
• Seconds through Centuries in BCD format
• Tracks Leap Years through 2099
• Uses Standard 32.768 kHz Crystal (6pF)
• Software Calibration
• Calibration Data is Nonvolatile
• Programmed Settings are Nonvolatile
• Supports Battery or Capacitor Backup
Processor Companion
• Active-low Reset Output for V_DD and Watchdog
• Programmable Low V_DD Reset Thresholds
• Manual Reset Filtered and Debounced
• Programmable Watchdog Timer
• Dual Battery-backed Event Counter Tracks System
Intrusions or other Events
• Comparator for Early Power-Fail Interrupt
• 64-bit Programmable Serial Number with Lock
Fast Two-wire Serial Interface
• Up to 1 MHz Maximum Bus Frequency
• Supports Legacy Timing for 100 kHz & 400 kHz
Easy to Use Configurations
• Operates from 2.7 to 5.5V
• Small Footprint 14-pin “Green” SOIC (-G)
• Low Operating Current
• -40°C to +85°C Operation
Description
The FM4005 is an integrated device that includes the
most commonly needed functions for processor-
based systems. Major features include real-time
clock, low-V_DD reset, watchdog timer, battery-backed
event counter, lockable 64-bit serial number area, and
general purpose comparator that can be used for a
power-fail (NMI) interrupt or other purpose. The
family operates from 2.7 to 5.5V.
The real-time clock (RTC) provides time and date
information in BCD format. It can be permanently
powered from external backup voltage source, either
a battery or a capacitor. The timekeeper uses a
common external 32.768 kHz crystal and provides a
calibration mode that allows software adjustment of
timekeeping accuracy.
The processor companion includes commonly needed
CPU support functions. Supervisory functions
include a reset output signal controlled by either a
low VDD condition or a watchdog timeout. /RST
goes active when VDD drops below a programmable
threshold and remains active for 100 ms after VDD
rises above the trip point. A programmable watchdog
timer runs from 100 ms to 3 seconds. The watchdog
timer is optional, but if enabled it will assert the reset
signal for 100 ms if not restarted by the host before
the timeout. A flag-bit indicates the source of the
reset.
A general-purpose comparator compares an external
input pin to the onboard 1.2V reference. This is
useful for generating a power-fail interrupt (NMI) but
can be used for any purpose. The device also includes
a programmable 64-bit serial number that can be
locked making it unalterable. Additionally it offers a
dual battery-backed event counter that tracks the
number of rising or falling edges detected on
dedicated input pins.
This is a product in pre-production phase of development. Device
characterization is complete and Ramtron does not expect to change
the specifications. Ramtron will issue a Product Change Notice if
any specification changes are made.
Rev. 2.3
Oct. 2006
Ramtron International Corporation
1850 Ramtron Drive, Colorado Springs, CO 80921
(800) 545-FRAM, [phone]
www.ramtron.com
Page 1 of 23