SNVS158E March 2001 – December 2016 LMS33460
PRODUCTION DATA.
7 Detailed Description
7.1 Overview
The LMS33460 is a micropower undervoltage-sensing circuit with an open-drain output configuration, which requires a pull resistor.
The LMS33460 features a voltage reference, a comparator with precise thresholds and built-in hysteresis to prevent erratic reset operation.
Figure 6. Propagation Delay Timing Diagram
Figure 7. Propagation Delay Test Circuit
7.2 Functional Block Diagram
7.3 Feature Description
The input supply (VIN) is the voltage that is being monitored and as it decreases past 3 V, the active-low output (VOUT) transitions to a logic low state. When VIN rises above 3 V plus the built-in hysterisis, VOUT returns to its original state of logic high. The LMS33460 has built-in hysteresis when the input supply is coming back up to help prevent erratic output operation when the input voltage crosses the threshold.
The LMS33460 is useful in a variety of applications that require low voltage detection and is suited for battery-powered systems where low quiescent current and small package size is required. It can also be used as a precision reset circuit for microcontroller applications.
7.4 Device Functional Modes
7.4.1 Start Up
As the input voltage (VIN) ramps up, the output (VOUT) remains logic low until VIN reaches 3.15 V due to the built-in hysteresis (nominally 150 mV). After VIN crosses that threshold, VOUT remains logic high until VIN drops below the 3-V threshold. The hysteresis only applies to the VIN rising threshold.