LM809M3-3.08

Supervisors Overview

The LM809M3-3.08/NOPB is a fixed-threshold voltage supervisory circuit manufactured by Texas Instruments, designed for microprocessor reset applications. It operates within a supply voltage range up to 5.5 V and features a precise 3.08 V threshold voltage with 5% accuracy. The device provides an active-low, push-pull output and includes a 240 ms reset delay time to ensure stable power-up sequencing. It is housed in a compact SOT-23-3 package and supports operation across an industrial temperature range of -40°C to +105°C.

Supervisors Feature Summary

• Provides a fixed 3.08 V threshold for accurate power supply monitoring
• Features an active-low, push-pull output driver for direct logic interface
• Includes a guaranteed 240 ms reset delay to prevent premature resets during power-up

Supervisors Applications

• Microprocessor system reset circuits
• Battery-powered equipment power supervision
• Portable instrumentation power monitoring

Supervisors Procurement Notes

Verify the specific suffix (e.g., /NOPB) against the manufacturer's current datasheet to confirm RoHS compliance and pinout configuration. Ensure the required threshold voltage matches the design specification exactly, as the LM809 series offers multiple fixed voltage options. Confirm that the active-low output polarity aligns with the target controller's reset input requirements before finalizing procurement.

Supervisors Selection Notes

Select this component when a fixed 3.08 V threshold is required for systems operating below 5.5 V. The active-low output makes it suitable for controllers requiring a low-level reset signal. Consider the 240 ms delay duration to ensure compatibility with the target processor's startup time requirements. Verify that the SOT-23-3 package fits the available PCB footprint constraints.

Supervisors Part Context

The LM809 belongs to the LM809/LM810 family of 3-pin microprocessor reset circuits from Texas Instruments. While the LM809 provides an active-low output, the companion LM810 variant offers an active-high output. Both share similar electrical characteristics and packaging, allowing for flexible design choices based on the required reset signal polarity for different microprocessor architectures.

Supervisors Replacement Considerations

The LM809M3-2.63/NOPB and LM809M3-4.38/NOPB are part of the same functional family but feature different threshold voltages. Direct substitution requires verifying that the alternative threshold voltage meets the system's power monitoring requirements. No other cross-manufacturer substitutes are confirmed in the provided documentation.