DS1233M-3+ Analog Devices

DS1233M EconoReset www.maxim-ic.com FEATURES PIN ASSIGNMENT Automatically restarts microprocessor after power failure DALLAS DS1233 1 8 NC Maintains reset for 350 ms after V returns RST CC Econo to an in-tolerance condition Reset 2 7 NC V CC Reduces need for discrete components 3 6 NC NC Precision temperature-compensated voltage 4 5 NC GND reference and voltage sensor Low-cost TO-92 package or surface mount DS1233M 8-Pin SOIC (150mil) 8-pin SOIC packages available See Mech. Drawings Internal 5 k pullup resistor Section on Website Compatible with Motorola 68XXX series and HC16 Microprocessors 1 2 3 Pin function compatible with the Motorola MC33064, MC34064, MC33164, and MC34164 Operating temperature of -40C to +85C 1 2 3 BOTTOM VIEW TO-92 PACKAGE See Mech. Drawings Section On Website PIN DESCRIPTIONS TO-92 1 RST - Active Low Reset Output 2 V - Power Supply CC 3 GND - Ground 8-Pin SOIC RST - Active Low Reset Output V - Power Supply CC NC - No Connect GND - Ground DESCRIPTION The DS1233M 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 (low) state. When V returns to an CC intolerance condition, the reset signal is kept in the active state for approximately 350 ms to allow the power supply and processor to stabilize. 1 of 4 041002 DS1233M OPERATION - POWER MONITOR The DS1233M 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. BLOCK DIAGRAM Figure 1 APPLICATION EXAMPLE Figure 2 2 of 4