Single-Chip USB-C buck-boost battery chargers support bidirectional power

Intersil Corporation today introduced two new USB-C™ buck-boost battery chargers that support bidirectional power delivery in ultrabooks, tablets, power banks and other mobile products. The single-chip ISL9238 and ISL9238A battery chargers replace competitive two-chip solutions to reduce customer bill of materials (BOM) costs by up to 40%. Both ICs employ Intersil’s patented R3™ modulation technology to extend battery life and deliver acoustic noise-free operation, superior light-load efficiency and ultra-fast transient response.

The ISL9238 and ISL9238A operate in forward buck, boost or buck-boost mode to fast charge mobile battery packs with up to 4-cell Li-ion batteries. They also support USB 3.1 On-The-Go (OTG) with 5V/20V reverse buck, boost or buck-boost mode to deliver power out of a USB-C port for charging external devices such as smartphones, headphones or virtual reality goggles. At maximum power, both ICs provide 20V at 5A to the USB-C port for delivery of power up to 100W over a reversible USB Type-C connector cable. The ISL9238A features the same capabilities as the ISL9238, but also includes a different SMBus address for OEMs that want to use both ICs to design systems with dual USB-C ports.

In charging mode, the ISL9238 and ISL9238A take input power from a wide range of DC power sources, including AC/DC charger adapters, USB power delivery (PD) ports and any travel adapter. Both chargers include SMBus and I2C programmable features such as depleted battery trickle charging, and a two-level adapter current limit for turbo-mode events where the charger takes advantage of the adapter’s milliseconds of surge current capability to minimize power draw and extend battery run-time. The ISL9238 and ISL9238A also feature programmable autonomous charging and an end of charge safety timer to stop battery charging.

“The new ISL9238/A USB-C buck-boost battery chargers give our customers more features, including 5V/20V reverse buck, boost and buck-boost modes, and the ability to add dual ports for two USB-C battery chargers in one system,” said Andrew Cowell, senior vice president of Mobile Power Products at Intersil. “Mobile computing OEMs rely on Intersil to consistently deliver power management innovations that help them differentiate their products with thinner form factors and exceptionally long battery life.”

The ISL9238 and ISL9238A are pin-compatible with the ISL9237 USB-C battery charger and join Intersil’s family of mobile computing power management solutions, including the ISL95852 Vcore PMIC, ISL95908 peripheral PMIC, and discrete PWM controllers (ISL95853/54/55/57). These ICs power IMVP8-compliant mobile systems using 6th and 7th Gen Intel® Core™ processors.

Key Features and Specifications of ISL9238 and ISL9238A

·        Buck-boost NVDC charger for 1-, 2-, 3-, or 4-cell Li-ion batteries

·        Input voltage range of 3.2V to 23.4V (no dead-zone)

·        System output voltage of 2.4V to 18.304V

·       Up to 1MHz operation allows use of smaller, lower cost inductors and automatically reduces switching frequency with no audible acoustic noise when charger is in DCM mode

·        ASGATE FET control: actively controls inrush current to prevent FET damage

·        Low-power and high-power LDO outputs tie to VDD pin to provide bias power and MOSFET gate drive power

·        Compliant with Intel PROCHOT# and PSYS for protection against battery voltage drop, adapter over-current, battery over-current and overheat

·        Allows trickle charging of depleted battery

·        Autonomous charging option provides end of charge control using safety timer to stop battery charging

·        SMBus/I2C programmable limit settings with adapter current monitor (AMON) and battery discharging current monitor (BMON)

·        Battery learn mode calibrates the battery fuel gauge

·        ISL9238A includes a different SMBus address to support charging a second battery

The ISL9238 and ISL9238A buck-boost battery chargers are available now and priced at $3.50 USD in 1k quantities. Both battery chargers are supplied in 4mm x 4mm, 32-lead TQFN packages.