ISL6124

The Intersil ISL6123, ISL6124, ISL6125, ISL6126, ISL6127, ISL6128 are integrated 4 channel controlled-on/controlledoff power-supply sequencers with supply monitoring, fault protection and a "sequence completed" signal (RESET#). For larger systems, more than 4 supplies can be sequenced by simply connecting a wire between SYSRESET# pins of cascaded IC's. The ISL6125 uses 4 open-drain outputs to control the 4 power supplies, and the other sequencers use a patented, micropower 7X chargepump to drive 4 external low-cost NFET switch gates above the supply rail by 5.3V. These IC's can be biased from any supply 5V down to 1.5V. Individual product descriptions are below.

The four channel ISL6123 (ENABLE input), ISL6124 (ENABLE# input) and ISL6125 ICs offer the designer 4 rail control when it is required that all four rails are in minimal compliance prior to turn on and that compliance must be maintained during operation. The ISL6123 has a low power standby mode when it is disabled, suitable for battery powered applications.

The ISL6125 operates like the ISL6124 but instead of charge pump driven gate drive outputs it has open drain logic outputs for direct interface to other circuitry. In contrast to the ISL6123 and ISL6124, with the ISL6126, each of the four channels operates independently so that the various rails will turn on once its individual input voltage requirements are met.

The ISL6127 is a preprogrammed A-B-C-D turn-on and D-CB- A turn-off sequenced IC. Once all inputs are in compliance and ENABLE is asserted the sequencing starts and each subsequent GATE will turn-on after the previous one completes turning-on.

The ISL6128 has two groups of two channels each with its independent I/O and is ideal for voltage sequencing into redundant capability loads as all four inputs need to be satisfied prior to turn on but a single group fault is ignored by the other group.

External resistors provide flexible voltage threshold programming of monitored rail voltages. Delay and sequencing are provided by external capacitors for both ramp up and ramp down.

Additional I/O is provided indicating and driving RESET state in various configurations.

For volume applications, other programmable options and features can be had. Contact the factory with your needs.