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X4043 Datasheet, PDF (1/25 Pages) Intersil Corporation – CPU Supervisor with 4kbit EEPROM | |||
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4K
X4043/45
512 x 8 Bit
CPU Supervisor with 4Kbit EEPROM
FEATURES
⢠Selectable watchdog timer
⢠Low VCC detection and reset assertion
âFive standard reset threshold voltages
âAdjust low VCC reset threshold voltage using
special programming sequence
âReset signal valid to VCC = 1V
⢠Low power CMOS
â<20µA max standby current, watchdog on
â<1µA standby current, watchdog OFF
â3mA active current
⢠4Kbits of EEPROM
â16-byte page write mode
âSelf-timed write cycle
â5ms write cycle time (typical)
⢠Built-in inadvertent write protection
âPower-up/power-down protection circuitry
âProtect 0, 1/4, 1/2, all or 16, 32, 64 or 128 bytes
of EEPROM array with Block Lock⢠protection
⢠400kHz 2-wire interface
⢠2.7V to 5.5V power supply operation
⢠Available packages
â8-lead SOIC
â8-lead MSOP
â8-lead PDIP
BLOCK DIAGRAM
DESCRIPTION
The X4043/45 combines 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 require-
ments, 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 protection
mechanism for microcontrollers. When the microcon-
troller 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 deviceâs low VCC detection circuitry protects the
userâs system from low voltage conditions, resetting the
system when VCC falls below the minimum VCC trip
point. RESET/RESET is asserted until VCC returns to
proper operating level and stabilizes. Five industry stan-
dard VTRIP thresholds are available, however, Xicorâs
unique circuits allow the threshold to be reprogrammed
to meet custom requirements or to ï¬ne-tune the thresh-
old for applications requiring higher precision.
WP
SDA
SCL
VCC
Watchdog Transition
Detector
Data
Register
Command
Decode &
Control
Logic
VCC Threshold
Reset logic
Protect Logic
Status
Register
EEPROM Array
+
VTRIP
-
Watchdog
Timer Reset
Reset &
Watchdog
Timebase
Power on and
Low Voltage
Reset
Generation
RESET (X4043)
RESET (X4045)
REV 1.1.17 9/14/01
www.xicor.com
Characteristics subject to change without notice. 1 of 25
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