Sync-buck controller bypasses intermediate step-down conversion stage

This technical achievement makes it possible for designers to reduce system complexity and solution cost in industrial, factory automation, medical and communications infrastructure applications.

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 V_OUT to V_IN ratio is low. The ISL8117 uses valley current mode modulation with adaptive slope compensation to enable stable operation for a wide range of V_OUT and V_IN combinations, with no external compensation required. System designers can also use the ISL8117’s adjustable frequency up to 2MHz to optimise 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  V_OUT and V_IN 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 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 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, 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.”

The ISL8117 is available now in 4mm² QFN and 6.4x5mm HTSSOP packages. Pricing for the QFN package is $1.80 and the HTSSOP is $1.95 in 1,000-unit quantities. Two evaluation boards priced at $80 allow designers to quickly evaluate device features and performance - the ISL8117EVAL1Z low power (V_IN 4.5V-60V and 3.3V_OUT/6A), and the ISL8117EVAL2Z high power (V_IN 18V-60V and 12V_OUT/20A).

Two demonstration reference design boards priced at $60 allow designers to produce low power (factory automation or robotic) and high power (telecomms or pachinko) applications.