X4043

® X4043, X4045 4k, 512 x 8 Bit Data Sheet September 30, 2005 FN8118.1 CPU Supervisor with 4kbit EEPROM FEATURES Selectable watchdog timer Low VCC detection and reset assertion —Five 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 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 www.DataSheet4U.com Available packages —8 Ld SOIC —8 Ld MSOP —8 Ld PDIP Pb-free plus anneal available (RoHS compliant) BLOCK DIAGRAM Watchdog Transition Detector WP SDA Data Register Command Decode & Control Logic VCC Threshold Reset logic Block Lock Control Protect Logic Status Register EEPROM Array 2Kbits 1Kb 1Kb 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 requirements, and increases reliability. Applying power to the device activates the power-on reset circuit which holds RESET/RESET active for a period...