UM809TS

Supervisors Overview

The UM809TS is a 3-pin microprocessor reset circuit from Union Semiconductor, part of the UM809/810 series. It monitors power supplies in digital systems and provides an active-low reset signal to the host processor when supply voltage falls below the threshold. The device features a fixed internal reset threshold and delay generator, eliminating external component adjustments. It 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 pulse width of 140ms after rising above the threshold. Supply current is 3 µA at VCC = 3V.

Supervisors Feature Summary

• Provides active-low reset signal for system supervision
• Internal fixed threshold and delay generator requiring no external adjustment
• Optimized to reject fast transient glitches on the power supply line
• Ultra-low supply current suitable for low power applications

Supervisors Applications

• CPU reset circuits
• Logic circuit supervision
• Portable electronic devices

Supervisors Procurement Notes

Verify the specific suffix 'TS' against official Union Semiconductor documentation to confirm package type (SC70-3 or SOT23-3) and temperature range. Ensure the active-low output characteristic matches the UM809 series specification rather than the UM810 active-high variant. Cross-reference the manufacturer's latest datasheet for any pinout variations or environmental compliance details associated with this specific marking code.

Supervisors Selection Notes

Select the UM809TS when an active-low reset output is required for microprocessor supervision. Choose this component for designs needing ultra-low quiescent current to extend battery life in portable applications. It is suitable for systems powered by +5V, +3.3V, or +3.0V rails where glitch immunity and precise timing delays are critical without external components.

Supervisors Part Context

The UM809TS belongs to the UM809/810 family of system supervisory circuits manufactured by Union Semiconductor. This series is designed to replace discrete monitoring solutions by integrating voltage reference, comparator, and delay functions into a single 3-pin package. The UM809 variant specifically provides an active-low output, distinguishing it from the UM810 which offers an active-high output.

Supervisors FAQ

What is the reset output polarity of the UM809TS?

The UM809TS provides an active-low reset output.

Does the UM809TS require external components for threshold setting?

No, the reset threshold and time delay are fixed internally with high accuracy and do not require external adjustment.