Features

• Simultaneously Monitors Four Supplies
• 16 User Selectable Combinations of 5V, 3.3V, 3V, 2.5V, 1.8V, 1.5V and/or ±Adjustable Voltage Thresholds
• Guaranteed Threshold Accuracy: ±1.5% of Monitored
  Voltage Over Temperature
• Selectable Supply Tolerance: 5%, 7.5%,
  10%, 12.5% Below Monitored Voltage
• Low Supply Current: 43µA Typ
• Adjustable Reset Time
• RESET Disable Pin for Margining Applications
• Open-Drain RST Output (LTC2902-1)
• Push-Pull RST Output (LTC2902-2)
• Individual Nondelayed Monitor Outputs for Each Supply
• Power Supply Glitch Immunity
• Guaranteed RESET for V_CC >/= 1V

Typical Application

Description

The LTC®2902 is a programmable supply monitor for systems with up to four supply voltages. One of 16 preset or adjustable voltage monitor combinations can be selected using an external resistor divider connected to the program pin. The preset voltage thresholds are digitally programmable to 5%, 7.5%, 10% or 12.5% below the nominal operating voltage, and are accurate to 1.5% over temperature. All four voltage comparator outputs are connected to separate pins for individual supply monitoring.

The reset delay time is adjustable using an external capacitor. Tight voltage threshold accuracy and glitch immunity ensure reliable reset operation without false triggering. The RST output is guaranteed to be in the correct state for V_CC down to 1V and may be disabled during supply margin testing. The LTC2902-1 features an open-drain RST output, while the LTC2902-2 has a push-pull RST output.

The 43µA supply current makes the LTC2902 ideal for power conscious systems and the part may be configured to monitor less than four inputs. The LTC2902-1/LTC2902-2 are available in the 16-lead narrow SSOP package.