ISL6128
Power Sequencing Controllers

Key Features

• Enables Arbitrary Turn-on and Turn-off Sequencing of Up to Four Power Supplies (0.7V to 5V)
• Operates From 1.5V to 5V Supply Voltage
• Supplies V_DD +5.3V of Charge Pumped Gate Drive
• Adjustable Voltage Slew Rate for Each Rail
• Multiple Sequencers Can be Daisy-Chained to Sequence an Infinite Number of Independent Supplies
• Glitch Immunity
• Undervoltage Lockout for Each Supply
• 1µA Sleep State (ISL6123, ISL6130)
• Active High (ISL6123, ISL6130) ENABLE or Low (ISL6124, ISL6125, ISL6126, ISL6127, ISL6128) ENABLE Input
• Active Open Drain Version Available (ISL6125)
• Voltage-determined Sequence (ISL6126, ISL6130)
• Pre-programmed Sequence Available (ISL6127)
• Dual Channel Groupings (ISL6128)
• QFN Package
• Pb-free (RoHS-compliant)

Description

The Intersil ISL6123, ISL6124, ISL6125, ISL6126, ISL6127, ISL6128 and ISL6130 are integrated 4-channel controlled-on/controlled-off power-supply sequencers with supply monitoring, fault protection and a “sequence completed” signal (RESET). For larger systems, more than four supplies can be sequenced by simply connecting a wire between the SYSRESET pins of cascaded ICs. The ISL6125 uses four active open-drain outputs to control the on/off sequencing of four supplies. The other sequencers use a patented, micropower 7x charge pump to drive four external low-cost NFET switch gates above the supply rail by 5.3V. These ICs can be biased from 5V down to 1.5V by any supply.

The 4-channel ISL6123 (ENABLE input), ISL6124 (ENABLE input) and ISL6125 offer the designer 4-rail control when all four rails must be in minimal compliance before turn-on and during operation. The ISL6123 and ISL6130 have a low-power standby mode when disabled, which is 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, for the ISL6126 and ISL6130, each of the four channels operates independently. Each GATE turns on once its individually associated input voltage requirements are met.

The ISL6127 is a pre-programmed A-B-C-D turn-on and D-C-B-A turn-off sequenced IC. Once all inputs are in compliance and ENABLE is asserted, sequencing begins. Each subsequent GATE turns on after the previous one turns on.

The ISL6128 has two groups of two channels, each with its independent I/O. It is ideal for voltage sequencing into redundant capability loads. All four inputs must be satisfied before 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 ramp-up and ramp-down.

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

For volume applications, other programmable options and features are available. Contact Intersil sales support with your needs.

Applications

• Graphics Cards
• FPGA/ASIC/Microprocessor/PowerPC Supply Sequencing
• Network Routers
• Telecommunications Systems