Intersil Introduces Three-Channel Wide Vin Step-Down Controllers

Intersil Corp. introduced two, three-channel synchronous step-down controllers which the company says deliver the industry’s most efficient, compact and flexible solutions for multi-output power supplies. These new devices are well suited for telecom and networking devices, internet gateways, cable modems, fiber optic modems, satellite set-top-boxes and various industrial applications.

The ISL9443 and ISL9444 incorporate three independent synchronous buck (step-down) controllers with flexible enable, tracking and sequencing features. The controllers’ 180 degree out-of-phase operation and internal compensation minimize ripple and reduce the need for external components. With an integrated 5V bias LDO, they can operate over a wide Vin range of 4.5V to 26V. The output voltage can be programmed from 0.7V to as high as 90% of Vin.

Diode emulation mode with pulse-skipping optimizes light-load efficiency and reduces standby current to only 30µA. For high power applications, the controllers include low resistance gate drivers to support up to 25A per channel. Programmable switching frequency of 200kHz to 1.2MHz (or external synchronization) and multiple protection capabilities provide designers with robust performance and optimal flexibility to tradeoff size versus efficiency.

The ISL9444 includes a number of additional features to enhance system functionality. It features a power failure monitor, three independent enables, and three independent Power Good signals, each with adjustable delay. An optional 5V bias input bypasses the internal LDO to reduce power dissipation within the package.

Pricing and Availability The ISL9443 is available in a 32-pin 5 x 5mm QFN package at $3.14 each in 1,000-unit quantities. The ISL9444 is available in a 40-pin 5 x 5mm QFN package for $3.23 each in 1,000-piece quantities.