DESCRIPTION
The LTC®1727 is a triple supply monitor intended for systems with multiple supply voltages. Each supply monitor has its own open-drain output for individual supply monitoring. A common open-drain reset output remains low until all three supplies have been in compliance for 200ms. Tight 1.5% accuracy specifications and glitch immunity ensure reliable reset operation without false triggering.
The LTC1728 is functionally identical to the LTC1727 without the individual monitor outputs.
The RST output is guaranteed to be in the correct state for VCC5/VCC25/VCC18 or VCC3 down to 1V. The LTC1727/LTC1728 may also be configured to monitor any one or two VCC inputs instead of three, depending on system requirements.
Very low (10µA typical) supply current makes the LTC1727/LTC1728 ideal for power conscious systems.
The LTC1727 is available in an 8-lead MSOP or SO package and the LTC1728 is available in a 5-lead SOT-23 package.

FEATURES
■ Monitors Three Inputs Simultaneously
   LTC1727-5: 5V, 3.3V and ADJ
   LTC1727-2.5: 2.5V, 3.3V and ADJ
   LTC1728-5: 5V, 3.3V and ADJ
   LTC1728-2.5: 2.5V, 3.3V and ADJ
   LTC1728-1.8: 3V, 1.8V and ADJ
■ ±1.5% Threshold Accuracy Over Temperature
■ Very Low Supply Current: 10µA Typ
■ 200ms Reset Time Delay
■ Active Low RESET Output
■ Power Supply Glitch Immunity
■ Guaranteed RESET for VCC3 ≥ 1V
   or VCC5/VCC25/VCC18 ≥ 1V
■ LTC1727 Includes Monitor Output for Each Supply
■ LTC1727: 8-Lead MSOP and SO Packages
■ LTC1728: 5-Lead SOT-23 Package

APPLICATIONS
■ Desktop Computers
■ Notebook Computers
■ Intelligent Instruments
■ Portable Battery-Powered Equipment
■ Network Servers