FM1233E

FM1233E 3-Pin µC Supervisor Circuit February 2003 FM1233E 3-Pin µC Supervisor Circuit General Description The FM1233E 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 accommodate 3V systems with different tolerances. The device features a precision temperature-compensated voltage reference and comparator. 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 FM1233E is of open-drain active low type. Features s Precision monitoring of 3.3V and lower voltage microprocessor systems s VTH values of 2.88V, 2.72V s Automatic restart of microprocessor after power failure s 140ms (min) power-on RESET delay (typ.: 256ms) s s s s Internal 5kΩ pull-up resistor Other reset choices available: 32 to 128ms Operating Temperature -40°C to +105°C SOT23-3 package Typical Operating Circuit VCC 3 FM1233E Controller 1 GND 2 RESET Connection Diagram GND 1 FM1233E 3 VCC RESET 2 SOT23-3 Package ©2003 Fairchild Semiconductor Corporation 1 www.fairchildsemi.com FM1233E Rev. D FM1233E 3-Pin µC Supervisor Circuit Absolute Maximum Ratings Voltage on any pin relative to GND VCC RESET Input Current Output Current (RESET) -0.3V to +6.0V -0.3V to (...