Digitally configurable USB-C combo buck-boost battery charger for mobile computing systems

Renesas Electronics has introduced the industry’s first USB-C buck-boost battery charger to support both NVDC and HPBB charging for tablets, notebooks, ultrabooks, and power banks using the reversible USB Type-C connector cable. Through firmware control, the ISL9241 is able to switch between NVDC and HPBB modes, giving a low-cost and small solution size offering efficient processing a full range of power levels. It leverages the company’s advanced R3 modulation technology for superior light-load efficiency and ultra-fast transient response to increase battery run-time. The charger’s reconfigurable internal registers enable the use of a smaller inductor for HPBB mode to deliver higher efficiencies across multiple power levels. The device provides charging, system bus regulation, and protection features using NFETs for highest efficiency and BOM cost optimisation. The charger can work with only a battery, only an adapter, or both connected. It takes DC input power from conventional adapters, travel adapters, and USB Type-C PD ports, and safely charges battery packs with up to four-cell Li-ion series batteries. In NVDC mode, the device automatically chooses the adapter or battery as the source for system power. NVDC operation also supports turbo mode by turning on the BGATE FET to limit adapter current at the adapter’s current limit set point. NVDC is the device’s initial startup state before the system controller’s firmware changes the configuration to HPBB. In higher power HPBB mode, the device supports bypass, bypass plus charging, reverse turbo-boost mode, and reverse turbo-boost mode plus charging. “The ISL9241 combo NVDC and HPBB battery charger gives customers the highest level of flexibility along with optimized system performance and maximum efficiency,” said Andrew Cowell, Vice President, Battery & Optical Systems Division, Renesas Electronics Corporation. “Mobile computing OEMs count on Renesas to consistently deliver power management innovations that help them differentiate their products with thinner form factors and longer battery life.”