Three-channel wide Vin step-down controllers provide design flexibility for multi-output power supplies
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 5 V bias LDO, they can operate over a wide Vin range of 4.5 V to 26 V. The output voltage can be programmed from 0.7 V to as high as 90 percent of Vin.
Diode emulation mode with pulse-skipping optimizes light-load efficiency and reduces standby current to only 30 µA, to deliver excellent light-load efficiency with low output voltage ripple. For high power applications, the controllers include low resistance gate drivers to support up to 25 A per channel. Programmable switching frequency of 200 kHz to 1.2 MHz (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 5 V bias input bypasses the internal LDO to reduce power dissipation within the package.
Other features include precision 1 percent voltage reference tolerance, internal compensation that supports all-ceramic output capacitors, and adaptive shoot-through protection with over-current, over-voltage and over-temperature protection.
Fore further information: www.intersil.com.