Features: •Selectable watchdog timer
•Low VCCdetection and reset assertion
-Five standard reset threshold voltages
-Adjust low VCCreset 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
•4kbits of EEPROM
-16-byte page write mode
-Self-timed write cycle
-5ms write cycle time (typical)
•Built-in inadvertent write protection
-Power-up/power-down protection circuitry
-Protect 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
-8 Ld SOIC
-8 Ld MSOP
-8 Ld PDIP
•Pb-free plus anneal available (RoHS compliant)Pinout
SpecificationsTemperature under bias ...................-65°C to +135°C
Storage temperature ........................-65°C to +150°C
Voltage on any pin with
respect to VSS......................................-1.0V to +7V
D.C. output current..................................................5mA
Lead temperature (soldering, 10 seconds).........300°CDescriptionThe 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 X4043 activates the power-on reset circuit which holds RESET</a>/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 X4043 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</a>/RESET signal. The userselects the interval from three preset values. Once selected, the interval does not change, even after cycling the power.
The X4043's low VCCdetection circuitry protects the user's system from low volt age conditions, resetting the system when VCCfalls below the minimum VCCtrip point. RESET</a>/RESET is asserted until VCCreturns to proper operating level and stabilizes. Five industry stan-dard VTRIPthresholds are avail able, however, Intersil's unique circuits allow the threshold to be reprogrammed to meet custom requirements or to fine-tune the thresh- old for applications requiring higher precision.
X4043 Data Sheet
