UM809TP

Supervisors Overview

The UM809TP is a 3-pin microprocessor reset circuit from Union Semiconductor, part of the UM809/810 series. It provides an active-low reset signal to host processors when power supply voltages drop below a specific threshold. The device operates with supply voltages including +5V, +3.3V, and +3.0V. Key electrical parameters include a reset output activation within 10 µs of falling through the threshold and a minimum reset hold time of 140ms after rising above the threshold. The supply current is 3 µA at VCC = 3V, and the reset output remains valid down to 1V.

Supervisors Feature Summary

• Provides active-low reset signals for digital system supervision
• Eliminates need for external components and manual adjustment
• Optimized to reject fast transient glitches on power lines
• Maintains correct logic state down to 1V supply voltage

Supervisors Applications

• CPU reset circuits
• Logic circuit supervision
• Power fail detection systems

Supervisors Procurement Notes

Verify the suffix 'TP' against official Union Semiconductor documentation to confirm package type (SC70-3 or SOT23-3) and temperature range specifications. Ensure the active-low output characteristic matches the design requirements, as opposed to the active-high UM810 variant. Cross-reference the specific threshold voltage options available in the datasheet to ensure compatibility with the target supply voltage.

Supervisors Selection Notes

Select the UM809TP for applications requiring an active-low reset output. Compare it with the UM810 series if an active-high output is preferred. Consider the low 3 µA supply current for battery-powered designs. Verify that the fixed internal delay generator meets the system's timing constraints without requiring external adjustments.

Supervisors Part Context

The UM809TP belongs to the UM809/810 family of ultra-low current system supervisory circuits manufactured by Union Semiconductor. These devices are designed to monitor power supplies in digital systems, offering reliability and cost-effectiveness by integrating voltage reference comparators, delay generators, and output drivers into a compact 3-pin package.

Supervisors FAQ

What is the reset output polarity of the UM809TP?

The UM809TP features an active-low reset output, distinguishing it from the UM810 series which has an active-high output.

How does the UM809TP handle power supply transients?

The device is optimized to reject fast transient glitches on the power supply line, ensuring stable operation.