Maxim Integrated MAX6880ETG

Description
The MAX6880-MAX6883 dual-/triple-voltage monitors are designed to sequence power supplies during power-up conditions. When all voltages exceed their respective thresholds, these devices turn on voltages to the system sequentially, enhancing n-channel MOSFETs used as switches. The time between each sequenced voltage is determined by an external capacitor, allowing flexibility in delay timing. The MAX6880/MAX6881 sequence three voltages, while the MAX6882/MAX6883 sequence two voltages.
These devices initially monitor all voltages, and when all are within their tolerances, internal charge pumps enhance external n-channel MOSFETs sequentially to apply voltages to the system. Internal charge pumps drive gate voltages 5V above the respective input voltage, ensuring MOSFETs are fully enhanced to reduce on-resistance.
The MAX6880-MAX6883 feature capacitor-adjustable slew-rate control for controlled turn-on characteristics. After all voltages reach 92.5% of their final value, a power-good output (MAX6880/MAX6882) signal is active. The power-good output (PG/RST) can be delayed with an external capacitor to create a power-on reset delay.
After the initial power-up phase, the MAX6880-MAX6883 continue to monitor voltages. If any voltage falls below its threshold, the MOSFETs are quickly turned off, and the voltages are tracked down together. An internal 1000 pulldown resistor ensures that capacitance at the MOSFET's source is discharged quickly. The power-good output goes low to provide a system reset.

Features
Capacitor-adjustable power-up sequencing delay
Internal charge pumps to enhance external n-channel FETs
Capacitor-adjustable timeout period power-good output (MAX6880/MAX6882)
Adjustable undervoltage lockout or logic-enable input
Internal 1000 pulldown for each output to discharge capacitive load quickly
0.5V to 5.5V nominal IN/OUT range
2.7V to 5.5V operating voltage range
Immune to short voltage transients
Small 4mm x 4mm 24-pin or 16-pin thin QFN packages

Applications
Multivoltage systems
Networking systems
Telecom
Storage equipment
Servers/workstations