Renesas Electronics ISL9241 USB-C buck-boost battery charger

Renesas Electronics’ ISL9241 USB-C buck-boost battery charger supports both Narrow Voltage Direct Charging (NVDC) and Hybrid Power Buck-Boost (HPBB) charging for notebooks, ultrabooks, tablets and power banks using the reversible USB Type-C connector cable.

Through firmware control, the product can switch between NVDC and HPBB modes, providing a small solution size capable of efficiently processing a full range of power levels. It leverages Renesas’s R3 modulation technology for light-load efficiency and ultrafast transient response to extend battery runtime. Reconfigurable internal registers allow the use of a smaller inductor for HPBB mode to achieve high efficiencies across multiple power levels.

The product delivers charging, system bus regulation and protection features. It can operate with only a battery, only an adapter or both connected. It takes DC input power from conventional adapters, travel adapters and USB Type-C power delivery (PD) ports and safely charges battery packs with up to four-cell Li-ion series batteries.

In NVDC mode, the device automatically selects 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 setpoint. In higher power HPBB mode, the charger supports bypass, bypass plus charging, reverse turbo-boost mode and reverse turbo-boost mode plus charging.

The product provides 5 to 20 V reverse buck, boost or buck-boost operation to the adapter port (OTG mode). This allows configurations to support USB-C PD output for fast-charging programmable power supply (PPS) ports. Direct charging the battery can also be enabled by bypassing the ISL9241 in PPS mode. The reconfigurable charging architecture allows designers to use the charger for multiport configurations while remaining fully compliant with the USB PD3.0 standard.

Several digital telemetry, fault monitoring and protection features are provided. The device also features a supplemental power mode that allows the input bias capacitor to store energy and release it during high power demand.