1

®

FN8131.1

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

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Copyright Intersil Americas Inc. 2005. All Rights Reserved

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X5323, X5325

(Replaces X25323, X25325)

CPU Supervisor with 32Kb SPI EEPROM

FEATURES

• Selectable watchdog timer

—Five standard reset threshold voltages

using special programming sequence

• Determine watchdog or low voltage reset with a

volatile flag bit

• Long battery life with low power consumption

—<50µA max standby current, watchdog on

—<1µA max standby current, watchdog off

—<400µA max active current during read

• 32Kbits of EEPROM

• Built-in inadvertent write protection

—Power-up/power-down protection circuitry

—Protect 0, 1/4, 1/2 or all of EEPROM array with

—In circuit programmable ROM mode

• 2MHz SPI interface modes (0,0 & 1,1)

• Minimize EEPROM programming time

—32-byte page write mode

—Self-timed write cycle

—5ms write cycle time (typical)

• 2.7V to 5.5V and 4.5V to 5.5V power supply

operation

• Available packages

—14 Ld TSSOP, 8 Ld SOIC, 8 Ld PDIP

• Pb-free plus anneal available (RoHS compliant)

DESCRIPTION

These devices combine four popular functions, Power-on

Reset Control, Watchdog Timer, Supply Voltage

Supervision, and Block Lock Protect Serial EEPROM

Memory in one package. This combination lowers

system cost, reduces board space requirements, and

increases reliability.

Applying power to the device activates the power-on

reset circuit which holds RESET/RESET active for a

period of time. This allows the power supply and oscilla-

tor to stabilize before the processor can execute code.

The Watchdog Timer provides an independent protec-

tion mechanism for microcontrollers. When the micro-

controller fails to restart a timer within a selectable

time

out

interval,

the

device

activates

the

RESET/RESET signal. The user selects the interval

from three preset values. Once selected, the interval

does not change, even after cycling the power.

user’s system from low voltage conditions, resetting the

proper operating level and stabilizes. Five industry stan-

unique circuits allow the threshold to be reprogrammed

to meet custom requirements or to fine-tune the thresh-

old for applications requiring higher precision.

BLOCK DIAGRAM

Watchdog

Timer Reset

Data

Register

Command

Decode &

Control

Logic

SI

SO

SCK

CS/WDI

Reset &

Watchdog

Timebase

Power-on and

Generation

+

-

RESET/RESET

Reset

Low Voltage

Status

Register

Protect Logic

8Kbits

8Kbits

16Kbits

Watchdog Transition

Detector

WP

X5323 = RESET

X5325 = RESET

Reset Logic

Data Sheet

October 27, 2005