FEATURES Precision Dual Voltage Monitor � VCC Supply Monitor - Dual reset outputs for complex microcontroller systems - Integrated memory write lockout function - No external components required Second Voltage Monitor Output � Separate VLOW output � Generates interrupt to MCU � Generates RESET for dual supply systems - Guaranteed output assertion to VCC - 1V Watchdog Timer � 1.6s Memory Internally Organized 2 x8 Extended Programmable Functions Available on SMS24 High Reliability � Endurance: 100,000 erase/write cycles � Data retention: 100 years OVERVIEW The S42xxx are a precision power supervisory circuit. It automatically monitors the device's VCC level and will generate a reset output on two complementary open drain outputs. In addition to the VCC monitoring, the S42xxx also provides a second voltage comparator input. This input has an independent open drain output that can be wireOR'ed with the RESET I/O or it can be used as a system interrupt. The S42xxx also has an integrated 4k/16k-bit nonvolatile memory. The memory conforms to the industry standard two-wire serial interface. In addition to the reset circuitry, the S42WD42/S42WD61 also has a watchdog timer.

Temperature Under Bias............................................................................................................................... to +85�C Storage Temperature..................................................................................................................................... to +125�C Soldering Temperature (less than 10 seconds)................................................................................................................... 300�C Supply Voltage............................................................................................................................................................. to 6.5V Voltage on Any Pin....................................................................................................................................... to VCC+0.3V ESD Voltage (JEDEC method).......................................................................................................................................... 2,000V

NOTE: These are STRESS ratings only. Appropriate conditions for operating these devices are given elsewhere in this specification. Stresses beyond those listed here may permanently damage the part. Prolonged exposure to maximum ratings may affect device reliability.

Symbol ICC ISB ILI ILO VIL VIH VOL Parameter Supply Current (CMOS) Standby Current (CMOS) Input Leakage Output Leakage Input Low Voltage Input High Voltage Output Low Voltage Conditions SCL = CMOS Levels @ 100KHz SDA = Open All other inputs = GND or VCC SCL = SDA = VCC All other inputs = GND VIN 0 To VCC VOUT 0 To VCC SCL, SDA, RESET# (pin 2) SCL, SDA, RESET (pin7) IOL = 3mA SDA VCC =5.5V VCC =3.3V VCC =5.5V VCC =3.3V Min Max 0.7xVCC 0.4 Units �A V

Symbol Parameter SCL Clock Frequency Clock Low Period Clock High Period Bus Free Time Start Condition Setup Time Start Condition Hold Time Stop Condition Setup Time Clock to Output Data Out Hold Time SCL and SDA Rise Time SCL and SDA Fall Time Data In Setup Time Data In Hold Time Noise Spike Width @ SCL, SDA Inputs Write Cycle Time Noise Suppression Time Constant SCL Low to SDA Data Out Valid SCL Low to SDA Data Out Change Before New Transmission Conditions

CAPACITANCE = 100KHz Symbol CIN COUT Parameter Input Capacitance Output Capacitance Max 5 8 Units pF