Power Sequencing Controllers

The Intersil ISL6123, ISL6124, ISL6125, ISL6126, ISL6127, ISL6128 and ISL6130 are integrated four 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 SYSRESET# pins of cascaded ICs. The ISL6125 uses four open-drain outputs to control the on/off sequencing of four supplies, while 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 any supply 5V down to 1.5V. Individual product descriptions follow.

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 VDD +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

• Under voltage lockout for each supply

• 1µA Sleep State (ISL6123, ISL6130)

• Active high (ISL6123, ISL6130) 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 with Pb-free plus anneal option (RoHS compliant)

Applications

• Graphics cards

• FPGA/ASIC/microprocessor/PowerPC supply sequencing

• Network routers

• Telecommunications systems