DS1834/A/D

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OPERATION

Power Monitor

The DS1834 provides the functions of detecting out-of-tolerance conditions on a 3.3-volt and 5-volt

power supply and warning a processor-based system of impending power failure. When an input is

detected as out of tolerance on either voltage input the RST for that supply will be forced active. When

that input returns to a valid state the RST will remain active for about 350 ms and then return to an

inactive state until the next input out-of-tolerance condition.

On power-up both resets are kept active for approximately 350 ms after the power supply inputs have

reached the selected tolerance. This allows the power supply and system power to stabilize before RST is

released.

All internal operating current for the DS1834 will be drawn from the input with the highest voltage level.

The outputs will draw current only from the controlling input (5V IN or 3.3V IN).

DS1834 BLOCK DIAGRAM Figure 1

DS1834A BLOCK DIAGRAM OUTPUT Figure 2