Innovative 60V synchronous buck controller simplifies power supply design

Latest from Intersil is the first 60V synchronous buck controller able to bypass the intermediate step-down conversion stage traditionally employed in industrial applications. The ISL8117 synchronous step-down PWM controller’s low duty cycle (40ns minimum on time) enables the direct step-down conversion from 48V to a 1V point-of-load. This technical achievement makes it possible for designers to reduce system complexity and solution cost in industrial, factory automation, medical and communications infrastructure applications, says the company. In high-voltage applications where a lower output voltage is required, designers have traditionally relied on modules that increase system cost, or two stage DC-DC solutions that increase solution footprint and complexity. The ISL8117 controller offers a cost-effective and reliable alternative for applications where Vout to Vin ratio is low. The ISL8117 uses valley current mode modulation with adaptive slope compensation to enable stable operation for a wide range of Vin and Vout combinations, with no external compensation required. System designers can also use the ISL8117’s adjustable frequency up to 2MHz to optimize power supply cost, size and efficiency. The innovative ISL8117 reduces solution footprint and simplifies design without compromising performance. Default design values for commonly used functions and the ISL8117’s wide Vin and Vout reduce the number of external components compared to competing solutions. With the ISL8117, engineers can design a complete DC-DC buck conversion solution with only 10 components, including MOSFETs and passives, and achieve up to 98% conversion efficiency with 1.5% output voltage accuracy. The ISL8117’s low pin count and layout friendly pin architecture also minimizes the number of overlapping traces, further improving power supply performance. “The ISL8117 buck controller addresses a growing need for direct POL conversion from very high input voltage such as 48V to 1V output,” said Mark Downing, senior vice president of infrastructure and industrial power products, Intersil. “The unique ability to support light load efficiency mode is critical in industrial applications and makes the ISL8117 a much better alternative than existing solutions based on older technology.” Key Features and Specifications 1 - Wide input voltage range of 4.5V to 60V covers all standard input rails including 5V, 12V, 24V, 36V, 42V and 48V 2 - Wide voltage output range is configurable from 0.6V to 54V 3 - Smallest min on time in the market, which enables a very low duty cycle power supply and eliminates the need for a two stage solution in many applications 4 - Programmable 100kHz to 2MHz switching frequency can be synchronized to reduce radiated system noise and avoid beat frequency issues 5 - Complete fault protection for long term reliability including over-voltage, under-voltage, over-current and over-temperature 6 - High current FET drivers and DEM mode operation ensures efficiency at all load levels 7 - Adjustable soft-start with pre-bias support enables the sequenced startup of multiple ISL8117 controllers The ISL8117 high voltage controller can be combined with Intersil low dropout linear regulators such as the ISL80136, ISL80138, ISL80101A, and integrated FET switching regulators (ISL8023/24 or ISL8016) to support the bulk power rails in a typical process control industrial application. The ISL8117 is available now in 4mm x 4mm QFN and 6.4mm x 5mm HTSSOP packages, says the company.