MB3793-42 Power-Voltage Monitoring IC with Watchdog Timer Description The MB3793 is an integrated circuit to monitor power voltage it incorporates a watchdog timer. A reset signal is output when the power is cut or falls abruptly. When the power recovers normally after resetting, a power-on reset signal is output to microprocessor units (MPUs). An internal watchdog timer with two inputs for system operation diagnosis can provide a fail-safe function for various application systems. The model number and package code are as shown below. Model No. Marking Code Detection Voltage MB3793-42 3793-A 4.2 V Features Precise detection of power voltage fall: 2.5% Detection voltage with hysteresis Low power dispersion: I = 27 A (reference) CC Internal dual-input watchdog timer Watchdog timer halt function (by inhibition terminal) Independently-set watchdog and reset times Mask option for detection voltage (4.9 to 2.4 V, 0.1-V steps) Two types of packages (SOP-8pin: 2 types) Application Arcade Amusement etc. Cypress Semiconductor Corporation 198 Champion Court San Jose, CA 95134-1709 408-943-2600 Document Number: 002-08515 Rev. *C Revised June 28, 2017 MB3793-42 Contents Description ...............................................................1 8.4 Inhibition operation (Positive clock pulse) ..12 Features ...................................................................1 8.5 Clock pulse input (Positive clock pulse) .....13 Application ...............................................................1 8.6 Inhibition input rising and falling time .........13 1. PIN ASSIGNMENT ..............................................3 9. OPERATION SEQUENCE .................................14 2. PIN DESCRIPTION ..............................................3 10. TYPICAL CHARACTERISTICS ......................15 3. BLOCK DIAGRAM ..............................................4 11. STANDARD CONNECTION ............................18 4. BLOCK FUNCTIONS ...........................................5 12. APPLICATION EXAMPLE ..............................19 12.1 Monitoring Single Clock ...........................19 5. ABSOLUTE MAXIMUM RATINGS ......................6 12.2 Watchdog Timer Stopping .......................19 6. RECOMMENDED OPERATING CONDITIONS ..6 13. NOTES ON USE ..............................................20 7. ELECTRICAL CHARACTERISTICS ...................7 14. ORDERING INFORMATION ...........................20 7.1 DC Characteristics .......................................7 7.2 AC Characteristics .......................................8 15. ROHS COMPLIANCE INFORMATION ...........20 8. TIMING DIAGRAM ...............................................9 16. PACKAGE DIMENSIONS ...............................21 8.1 Basic operation (Positive clock pulse) ........9 17. MAJOR CHANGES .........................................23 8.2 Basic operation (Negative clock pulse) ......10 Document History .................................................23 8.3 Single-clock input monitoring (Positive clock Sales, Solutions, and Legal Information .............24 pulse) ................................................................11 Document Number: 002-08515 Rev. *C Page 2 of 24