特点
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
典型应用
描述
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.