Date: 09/09/2011

3-channel, 4.5 - 26V input step-down controllers for designing compact power supplies

Intersil Corporation has introduced two, three-channel synchronous step-down controllers that deliver the compact and flexible solutions for multi-output power supplies, which are suitable for telecom and networking devices, internet gateways, cable modems, fiber optic modems, satellite set-top-boxes and various industrial applications.

Intersil says the ISL9443 and ISL9444 consists of three independent synchronous buck (step-down) controllers with flexible enable, tracking and sequencing features, and the controllers' 180 degree out-of-phase operation and internal compensation minimize ripple and reduce the need for external components. The output voltage can be programmed from 0.7V to as high as 90% of Vin. For high power applications, the controllers include low resistance gate drivers to support up to 25 amps per channel.

The ISL9444 also features 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.

Features and specifications of ISL9444 include:
Wide input voltage range of 4.5V to 26V
32uA (typical) standby current delivers excellent light-load efficiency with low output voltage ripple
Precision 1% voltage reference tolerance
Adjustable switching frequency of 200kHz to 1.2MHz permits user tradeoff between efficiency and size
Internal compensation supports all-ceramic output capacitors
Adaptive shoot-through protection with over-current, over-voltage and over-temperature protection

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

For more information visit: www.intersil.com