LM809M3-4.38/NOPB

Supervisors Overview

The LM809M3-4.38/NOPB is a voltage supervisory integrated circuit manufactured by Texas Instruments, designed for monitoring single-channel power supply voltages. It operates within a maximum supply voltage of 5.5 V and features an active-low, push-pull output configuration. The device triggers a reset signal when the monitored input falls below a precise threshold of 4.38 V. It includes a fixed reset delay time of 140 ms to ensure system stability during power transitions. The component supports surface-mount installation in a compact SOT-23-3 package and functions reliably across an extended industrial temperature range from -40°C to +105°C.

Supervisors Feature Summary

• Provides active-low push-pull reset signaling for reliable logic interface compatibility
• Monitors a single voltage input channel with high precision threshold detection
• Operates without manual reset controls or watchdog timer functionality
• Supports surface-mount assembly in a space-efficient three-terminal package

Supervisors Applications

• Microprocessor system hardware monitoring
• Power supply supervision in embedded controllers
• Battery backup switching circuits
• Industrial control system voltage tracking

Supervisors Procurement Notes

Verify the complete part number including the suffix /NOPB to confirm lead-free compliance and RoHS status. Confirm the specific threshold voltage variant matches the design requirement, as the LM809 family offers multiple options. Check the datasheet for accurate reset delay timing characteristics relative to load conditions. Ensure the operating temperature range aligns with the intended environmental application constraints.

Supervisors Selection Notes

Select this component when a simple, low-pin-count supervisor is required for single-rail monitoring. The SOT-23-3 package suits applications with strict board space limitations. Consider the 140 ms reset delay duration against system startup requirements. Evaluate the 5% accuracy specification against the tolerance needs of the monitored circuit. This device lacks manual reset inputs, so design accordingly if user intervention is necessary.

Supervisors Part Context

This part belongs to the LM809 series of supervisory circuits from Texas Instruments. The series provides basic power-on reset functionality for digital systems. The M3 designation indicates a specific manufacturing revision or traceability code. The NOPB suffix confirms the absence of lead-based solder finishes, adhering to modern environmental standards for electronic components distributed globally.

Supervisors Replacement Considerations

Public documentation identifies LM809M3-2.93/NOPB as an alternate option within the same family, differing primarily in threshold voltage. Verify pinout compatibility before substitution. Other LM809 variants may share the package but require validation of electrical parameters such as reset delay and quiescent current.