DC/DC step-down controller IC for high-power systems

EDN Europe, 09 Jan 2009

MAX15034 is a dual-output, synchronous step-down controller capable of driving external MOSFETs to deliver two 25A outputs or a single 50A output. You can use it in designs over multiple projects to reduce inventory and cost. It operates from a 4.5V to 28V input range, allowing it to be used in both 5V- and 12V-bus applications. Maxim intend it for applications requiring a high output current such as computing, telecom, networking, storage, and server equipment. Programmable features include output voltage (0.6V to 5.5V), switching frequency (100 kHz to 1 MHz), current-limit threshold, and the external compensation network. The device employs an average current-mode scheme that provides current-limit and current-sharing accuracy of better than 10% between phases. The accurate current limit eliminates the need for oversized external MOSFETs and inductors, Maxim says. It will also start up monotonically when the output has a prebiased voltage; two enable inputs with accurate turn-on thresholds allow output-voltage sequencing; you can synchronise its frequency to an external reference; and there are thermal-shutdown and hiccup-mode protections. The MAX15034 is available in either a 28-pin TSSOP or a 28-pin TSSOP with exposed pad, operates over the -40 to +125C automotive temperature range and costs $2.56 (1000).