DS1233DZ-5+ Analog Devices

DS1233D 5V EconoReset www.maxim-ic.com FEATURES PIN ASSIGNMENT Automatically restarts microprocessor after power failure 1 DALLAS DS1233 Maintains reset for 350 ms after V returns CC Econo Reset to an in-tolerance condition Accurate 5%, 10% or 15% microprocessor 5V power supply monitoring 2 4 3 Reduces need for discrete components TOP VIEW SOT-23 PACKAGE Precision temperature-compensated voltage See Mech. reference and voltage sensor Drawings Section On Website 1 2 3 Low-cost TO-92 package or surface mount SOT-223 package 1 2 3 Internal 5 k pull-up resistor Compatible with Motorola 68XXX series and BOTTOM VIEW HC16 Microprocessors TO-92 PACKAGE See Mech. Operating temperature of -40C to +85C Drawings Section On Website PIN DESCRIPTION PIN 1 GROUND PIN 2 RESET PIN 3 V CC PIN 4 GROUND (SOT-223 ONLY) DESCRIPTION The DS1233D EconoReset uses a precision temperature-compensated reference and comparator circuit to monitor the status of the power supply (V ). When an out-of-tolerance condition is detected, an internal CC power-fail signal is generated which forces reset to the active state. When V returns to an in-tolerance CC condition, the reset signal is kept in the active state for approximately 350 ms to allow the power supply and processor to stabilize. OPERATION - POWER MONITOR The DS1233D provides the functions of detecting out-of-tolerance power supply conditions and warning a processor-based system of impending power failure. When V is detected as out of tolerance as CC defined by the tolerance of the part selected, the RST signal is asserted. On power-up, RST is kept active for approximately 350 ms after the power supply has reached the selected tolerance. This allows the power supply and microprocessor to stabilize before RST is released. 1 of 5 041002DS1233D BLOCK DIAGRAM Figure 1 APPLICATION EXAMPLE Figure 2 2 of 5