STMicroelectronics Comparator with Fail-Safe and Start-Up Time Assurance Enhances Reliability and Saves Power

STMicroelectronics' TS3121 and TS3121A are rail-to-rail, open-drain, single-channel comparators featuring an innovative fail-safe architecture and start-up time assurance, designed to simplify the start-up process and minimize power consumption in low-power applications.

The fail-safe architecture ensures that the voltage at the input analog sensor remains stable when the power supply is disconnected, thereby ensuring reliable comparator performance and simplifying firmware design for applications. The start-up time assurance feature allows for frequent switching of the device’s power supply, extending the off-time and maximizing power savings.

Inspired by industrial robotics sensors, the new comparators are designed to save power by relying on a backup battery to power position sensing functions when the main system power is off. Both comparators meet the demands of various automation applications and offer independent power, I/O ports, and output voltage domains, enabling flexible level shifting. These features make them highly suitable for industrial control, building automation, power tools, and smart metering applications. Additionally, the TS3121 and TS3121A come in automotive-grade versions, ideal for applications in powertrain and body control modules.

The new comparators operate within a supply voltage range of 1.7V to 5.5V and feature a precise input stage for accurate threshold detection, with a typical propagation delay of 60ns. Both devices have a typical input offset voltage of 0.5mV, with a maximum offset voltage of 2mV for the TS3121A and 6mV for the TS3121. Both comparators offer electrostatic discharge (ESD) protection up to 4kV (HBM) and have an operating temperature range from -40°C to 125°C. They come in space-saving SC70-5 and standard SOT23-5 packages.

The TS3121 and TS3121A are now available and free samples can be requested from ST's eStore. Both comparators are part of STMicroelectronics' 10-year long-term supply program, ensuring a steady supply over the long term.