X80204

The X80200 power sequencer provides a flexible approach for handling difficult system power-up conditions. The X80200 includes control of up to three voltage supplies and can be cascaded to control additional supplies. The device
contains independent undervoltage lockout for each controlled voltage.

The three voltage control circuits allow sequencing for primary, core, and I/O voltages. The core and I/O supplies are linked together with a comparator or a timer allowing a tight coupling between these two supplies. The sequencing may be either voltage based or time based. The X80200 contains separate charge pumps to control external N-channel power FETs for each of the supplies. The charge pumps provide the high gate control voltage necessary for efficient operation of the FET switches.

The X80200 turns on the primary voltage to the system when the voltage source is steady. This primary FET switch turn-on can be delayed with an external RC circuit. For the secondary voltage sources, the device has a built-in "coreup-first and core-down-last" sequencing logic which is ideal for high performance processors, DSPs and ASICs.
The serial bus can be used to monitor the status or turn off each of the external power switches. The X80200 has 3 slave address bits that allow up to 8 devices to be connected to the same bus.