FM803LS3X

Supervisors Overview

The FM803LS3X is a 3-pin voltage supervisor circuit manufactured by Fairchild Semiconductor. It monitors system supply voltages and generates a reset signal to ensure proper microprocessor operation during power-up, power-down, or brown-out conditions. The device operates within a specified input voltage range and provides a stable output state when the monitored voltage falls below or exceeds defined thresholds. Designed for surface-mount installation in the SOT-23 package, it offers reliable supervision for digital logic circuits with low quiescent current consumption.

Supervisors Feature Summary

• Provides automated reset signal generation upon detection of under-voltage or over-voltage events
• Ensures correct initialization of microprocessors and memory devices during power transitions
• Features low power consumption suitable for battery-operated systems

Supervisors Applications

• Microprocessor reset circuits in embedded systems
• Brown-out protection for portable electronic devices
• Power management supervision in industrial control units

Supervisors Procurement Notes

Verify the manufacturer origin as Fairchild Semiconductor, noting its acquisition by ON Semiconductor. Confirm the specific suffix LS3X corresponds to the intended package and temperature grade. Request official datasheets to validate electrical characteristics against design requirements before integration.

Supervisors Selection Notes

Select this component when a dedicated voltage supervisor is required for single-supply monitoring. Ensure the trip point voltage matches the system's minimum operating level. Consider the SOT-23 footprint constraints and thermal performance relative to the application environment.

Supervisors Part Context

Fairchild Semiconductor was acquired by ON Semiconductor, and its product line continues under the ON Semi brand. The FM803 series belongs to the standard analog and mixed-signal portfolio designed for general-purpose voltage supervision. This part represents legacy inventory from the Fairchild era, now supported through ON Semiconductor distribution channels.

Supervisors Replacement Considerations

Compatible substitutes include FM1233A, FM1233B, FM1233D, FM1233E, and FM809 from Fairchild/ON Semiconductor. Cross-reference pinouts and trip voltages carefully when substituting.