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Power Sequencing Controllers

ISL6123, ISL6124, ISL6125,

ISL6126, ISL6127, ISL6128,

ISL6130

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

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.

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

• 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

• 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)

Applications

• Graphics Cards

• FPGA/ASIC/Microprocessor/PowerPC Supply Sequencing

•Network Routers

• Telecommunications Systems

FIGURE 1. TYPICAL ISL6123 APPLICATION

AOUT

AIN

BIN

CIN

DIN

BOUT

COUT

DOUT

UVLO_B

UVLO_A

UVLO_D

UVLO_C

ENABLE

SYSRST

GROUND

RESET

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-468-3774

Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.

All other trademarks mentioned are the property of their respective owners.

August 25, 2011

FN9005.11