Features

• Two Low Voltage Adjustable Inputs (0.5V)
• Pin Selectable Input Polarity Allows Negative and OV Monitoring
• Guaranteed Threshold Accuracy: ±1.5%
• 6.5V Shunt Regulator for High Voltage Operation
• Low 50μA Quiescent Current
• Buffered 1V Reference for Negative Supply Offset
• Input Glitch Rejection
• Adjustable Reset Timeout Period
• Selectable Internal Timeout Saves Components
• Open-Drain RST Output
• Accurate UVLO for 2.5V, 3.3V, 5V Systems
• Ultralow Voltage Reset: VCC = 0.5V Guaranteed
• Space Saving 8-Lead TSOT-23 and 3mm × 2mm DFN Packages

Typical Application

Description

The LTC2909 is a dual input monitor intended for a variety of system monitoring applications. Polarity selection and a buffered reference output allow the LTC2909 to monitor positive and negative supplies for undervoltage (UV) and overvoltage (OV) conditions.

The two inputs have a nominal 0.5V threshold, featuring tight 1.5% threshold accuracy over the entire operating temperature range. Glitch filtering ensures reliable reset operation without false triggering. A third fixed-threshold UVLO monitor on the part’s VCC (also 1.5% accuracy) is available for standard logic supplies.

The common reset output has a timeout that may use a preset 200ms, be set by an external capacitor or be disabled. A three-state input pin sets the input polarity of each adjustable input without requiring any external components.

The LTC2909 provides a highly versatile, precise, space conscious, micropower solution for supply monitoring.