®
Data Sheet
X4323, X4325
32k, 4k x 8 Bit
May 25, 2006
FN8122.1
CPU Supervisor with 32k EEPROM
FEATURES
• Selectable watchdog timer
• Low VCC detection and reset assertion
—Four standard reset threshold voltages
—Adjust low VCC reset threshold voltage using
special programming sequence
—Reset signal valid to VCC = 1V
• Low power CMOS
—<20µA max standby current, watchdog on
—<1µA standby current, watchdog off
—3mA active current
• 32Kbits of EEPROM
—64-byte page write mode
—Self-timed write cycle
—5ms write cycle time (typical)
• Built-in inadvertent write protection
—Power-up/power-down protection circuitry
—Block Lock (1, 2, 4, 8 pages, all, none)
• 400kHz 2-wire interface
• 2.7V to 5.5V power supply operation
• Available packages
— 8 Ld SOICwww.DataSheet4U.com
—8 Ld TSSOP
• Pb-free plus anneal available (RoHS compliant)
BLOCK DIAGRAM
DESCRIPTION
The X4323, X4325 combines four popular functions,
Power-on Reset Control, Watchdog Timer, Supply Volt-
age Supervision, and 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.
The device’s low VCC detection circuitry protects the
user’s system from low voltage conditions, resetting the
system when VCC falls below the set minimum VCC trip
point. RESET/RESET is asserted until VCC returns to
proper operating level and stabilizes. Four industry
standard VTRIP thresholds are available, however, Inter-
sil’s unique circuits allow the threshold to be repro-
grammed to meet custom requirements or to fine-tune
the threshold for applications requiring higher precision.
WP
SDA
SCL
S0
S1
VCC
Watchdog Transition
Detector
Protect Logic
Data
Register
Command
Decode &
Control
Logic
VCC Threshold
Reset logic
Status
Register
EEPROM Array
VTRIP
+
-
Watchdog
Timer Reset
Reset &
Watchdog
Timebase
Power-on and
Low Voltage
Reset
Generation
RESET (X4323)
RESET (X4325)
1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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