DS1238A

DS1238A MicroManager www.dalsemi.com FEATURES Holds microprocessor in check during power transients Halts and restarts an out-of-control microprocessor Warns microprocessor of an impending power failure Converts CMOS SRAM into nonvolatile memory Unconditionally write protects memory when power supply is out of tolerance Delays write protection until completion of the current memory cycle Consumes less than 200 nA of battery current Controls external power switch for high current applications Debounces pushbutton reset Accurate 10% power supply monitoring Optional 5% power supply monitoring designated DS1238A-5 Provides orderly shutdown in microprocessor applications Pin-for-pin compatible with MAX691 Standard 16-pin DIP or space-saving 16-pin SOIC Optional industrial temperature range -40°C to +85°C PIN ASSIGNMENT VBAT VCCO VCC GND PF RVT OSCIN OSCSEL 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 RST RST WDS CEI CEO ST NMI IN VBAT VCCO VCC GND PF RVT OSCIN OSCSEL 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 RST RST WDS CEI CEO ST NMI IN 16-Pin DIP (300-mil) See Mech. Drawings Section 16-Pin SOIC (300-mil) See Mech. Drawings Section PIN DESCRIPTION VBAT VCCO VCC GND PF RVT OSCIN OSCSEL IN NMI ST CEO CEI WDS RST RST - +3-Volt Battery Input - Switched SRAM Supply Output - +5-Volt Power Supply Input - Ground - Power-Fail - Reset Voltage Threshold - Oscillator In - Oscillator Select - Early Warning Input - Non-Maskable Interrupt - Strobe Input - Chip Enable Output - Chip Enable Input -...