The chip supplier follows through with rapid-charging solutions for mobile electronics.

When MediaTek Inc. joined the fast-charging fray with its Pump Express technology, chipmakers such as Dialog Semiconductor plc have responded with an array of AC/DC adapter components.

Dialog claims to be the first company to ship mobile device adapter solutions based on the former's protocol for smartphones and tablet computers. Earlier, it also took the lead in releasing adapter ICs based on Qualcomm's Quick Charge 2.0 standard. "The two major players - Qualcomm and MediaTek - own 80 percent of the market," said Davin Lee, senior vice president and general manager of Dialog's power conversion business group.

Conventional USB chargers provide a fixed 5V supply, which requires a buck converter inside a terminal device to switch to the appropriate output voltage. MediaTek's Pump Express technology incorporates both power management ICs in mobile electronic products and corresponding AC/DC wall chargers through SoCs.

The Pump Express is said to cut charging time by up to 50 percent. "It enables a smartphone or tablet PC to negotiate with the AC/DC wall charger to find out the initial voltage needed to recharge the battery given the available current," said Jeffrey Ju, general manager of MediaTek's smartphone business unit. "Then, the voltage is gradually increased up to 5V to boost the charging current."

The technology is available in two formats according to the battery capacity. The original Pump Express suits AC/DC wall chargers with an output of less than 10W or 5V. The high-power Pump Express Plus standard supports up to 12V, allowing power transfer at 15W or more.

Rapid charging marks the shift to intelligent devices. "The charger communication protocols perform voltage configuration on the fly, depending on the state of the battery," said Dialog's Lee.

Dialog introduced initially the iW1680 AC/DC controller, a single-chip solution compliant with MediaTek's Pump Express for up to 45 percent faster charging than conventional counterparts. Then, it unveiled the iW1788 based on the Pump Express Plus standard.

Eyeing the next billion smartphones

Communication with the iW1788 AC/DC controller takes place through the VBUS supply line. The chip uses digital algorithms to detect commands from phones and tablet computers compatible with MediaTek's Pump Express Plus protocol, and scales dynamically the charger's output voltage to 12V from 3.6V.

"The iW1788 chip embeds digital analysis on the primary side of the isolated power supply in the charger, and eliminates the need for a secondary-side regulator and optoisolator," Lee said.

In addition, Dialog's AC/DC controller chips bring no additional BOM cost. The iW1680 and iW1788 meet global energy efficiency standards, including the US DOE final ruling and the EU Code of Conduct version 5, tier 2.

Power component suppliers such as Dialog are supporting MediaTek's rapid-charging technology because of the latter company's dominant position in China's smartphone processor market.

Although MediaTek entered the market much later than Qualcomm, it is more aggressive, given its large market share there. "MediaTek offers a cheaper solution and is eyeing the next billion smartphones from China handset suppliers," Lee added. "The growth rate of smartphones in 2014 is about 5 percent, while that of charging products is nearly 30 percent."

Contributed by Majeed Ahmad, author of Smartphone, Nokia's Smartphone Problem, Mobile Commerce 2.0, Essential 4G Guide and Age of Mobile Data: The Wireless Journey to All Data 4G Networks. Majeed has been writing for technology and trade media for more than 18 years.