FM1233B Datasheet | Fairchild Semiconductor

Description The FM1233B is a supervisor circuit that monitors a microprocessor power supply or other system voltage and issues a reset pulse when a fault condition exists. Several different threshold voltages are offered to acmodate 5V systems with different tolerances. The device features a precision temperature-pensated voltage reference and parator. When VCC falls to the threshold voltage, a RESET pulse is issued, holding the output in the active state. When power rises above VTH, the reset remains for approximately 250 ms to allow the system clock and other circuits to stabilize. The reset output of FM1233B is of open-drain active low type. The FM1233B also can monitor a switch closure on its output, enabling it to recognize an external reset from a pushbutton switch or a µP. In the case of a switch, the closure will be debounced by circuitry internal to the FM1233B. Features s Precision monitoring of 5V and lower voltage microprocessor systems s VTH values of 4.62V, 4.38V and 4.12V s Automatic restart of microprocessor after power failure s 140ms (min) power-on RESET delay (typ.: 256ms) s s s s s s Internal 5kΩ pull-up resistor Other reset choices available: 32 to 128ms Operating Temperature -40°C to +105°C Monitors external pushbutton override Internal switch debounce circuitry SOT23-3 package Typical Operating Circuit FM1233B Controller Connection Diagram RESET 1 FM1233B 3 VCC RESET SOT23-3 Package ©2002 Fairchild Semiconductor Corporation .fairchildsemi. FM1233B Rev. D FM1233B 3-Pin µC Supervisor Circuit Absolute Maximum Ratings Votage on any pin relative to GND VCC RESET Input Current Output Current (RESET) ESD Rating: Human body model >2k V Machine Model >200 V Continuous Power Dissipation (TA = 70°C) SOT23 (derate 4m W above 70°C) 300m W 20m A Operating Temperature Range -40°C to +105°C Storage Temperature Range -65°C to +150°C Lead Temperature (soldering, 10s) +300°C These are stress ratings only, and functional...