www.DataSheet4U.com
19-3772; Rev 1; 10/05
Dual-/Triple-Voltage, Power-Supply Sequencers/Supervisors
General Descriptio...
www.DataSheet4U.com
19-3772; Rev 1; 10/05
Dual-/Triple-
Voltage, Power-Supply Sequencers/Supervisors
General Description
The MAX6880–MAX6883 dual-/triple-
voltage monitors are designed to sequence power supplies during power-up condition. When all of the
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, thus allowing flexibility in delay timing. The MAX6880/MAX6881 sequence three
voltages and the MAX6882/MAX6883 sequence two
voltages. These devices initially monitor all of the
voltages and when all of them are within their tolerances, the internal charge pumps enhance external n-channel
MOSFETs in a sequential manner to apply the
voltages to the system. Internal charge pumps drive the gate
voltages 5V above the respective input
voltage thereby ensuring the
MOSFETs are fully enhanced to reduce the on-resistance. The MAX6880–MAX6883 feature capacitor-adjustable slew-rate control to provide controlled turn-on characteristics. After all of the
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 the
voltages. If any of the
voltages falls below its threshold, the
MOSFETs are quickl...