DS1233A

DS1233A 3.3V EconoReset www.maxim-ic.com FEATURES § § § § § § § § § § Automatically restarts microprocessor after power failure Monitors pushbutton for external override Internal circuitry debounces pushbutton switch Maintains reset for 350ms after VCC returns to an in-tolerance condition or pushbutton released Accurate 10% or 15% microprocessor 3.3V power supply monitoring Reduces need for discrete components Precision temperature-compensated voltage reference and voltage sensor Low-cost TO-92 package or surface mount SOT-223 package Internal 5kW pull-up resistor Operating temperature of -40°C to +85°C PIN ASSIGNMENT DALLAS DS1233A Econo Reset 1 1 2 3 1 2 3 BOTTOM VIEW TO-92 PACKAGE See Mech. Drawings Section on Website 2 4 3 TOP VIEW SOT-223 PACKAGE See Mech. Drawings Section on Website PIN DESCRIPTION PIN 1 PIN 2 PIN 3 PIN 4 GROUND RESET VCC GROUND (SOT-223 ONLY) DESCRIPTION The DS1233A EconoReset monitors two vital conditions for a microprocessor: power supply and external override. A precision temperature-compensated reference and comparator circuit are used to monitor the status of the power supply (VCC). When an out-of-tolerance condition is detected, an internal power fail signal is generated which forces reset to the active state. When VCC returns to an in-tolerance condition, the reset signal is kept in the active state for approximately 350ms to allow the power supply and processor to stabilize. The second function of the DS1233A is pushbutton reset control. ...