Device targets China tablet and smartphone market

The iW1788 is a single-chip adapter solution that significantly reduces charge times in USB AC/DC wall chargers for high battery capacity smartphones and tablets. It uses Dialog’s built-in, intelligent rapid charge digital algorithm to detect commands from smartphones and tablets designed with MediaTek’s Pump Express Plus-compatible MT6595 octa-core LTE processors. The high power Pump Express Plus protocol enables the phone or tablet to request voltages as high as 12V from the power adapter to provide safe and reliable power transfer at 15W or more. This reduces charge times through more efficient power transfer to the battery.

Built on Dialog’s latest PrimAccurate™ primary-side controller topology, the iW1788 Rapid Charge AC/DC controller embeds sophisticated digital analysis on the primary side of the isolated power supply within the charger, eliminating the need for intelligence on the secondary side. PrimAccurate primary-side feedback also eliminates the need for a secondary-side regulator and opto-isolator for a simple, low component count solution.

“The biggest shift in smartphone and tablet adapters is the move to fast charging and we expect broad adoption of fast charge protocols in the second half of 2014, particularly in the China market,” said Mark Tyndall, Senior VP Corporate Development & Strategy, GM Power Conversion Business Group at Dialog Semiconductor. “With the introduction of our iW1788 Pump Express Plus compatible controller, we address the higher power-class smartphone and tablet market. Combined with the launch of our iW1680 lower power Pump Express controller in March, this further cements Dialog’s position as the leading supplier of Rapid Charge adapter solutions.”

The iW1788 supports power adapters up to 15W, with high active average efficiency, low no-load power consumption less than 30mW, and a low cost bill of materials. This provides a high power density solution that supports fast charging for higher capacity smartphone and tablet batteries without increasing the size of the adapter. The high efficiency also helps ensure that specified thermal requirements for the adapter case are not exceeded.

Communication between the phone and iW1788 is through the VBUS supply line. The iW1788 digitally manages voltage scaling on the primary side of the transformer in the AC/DC adapter by analyzing the signal on the VBUS and scaling its output voltage accordingly from 3.6V to 12V. The iW1788 also offers a full array of protection features including overvoltage, short circuit and over-temperature protection.The iW1788 comes in a standard 8-pin SOIC package. Full protection features include built-in output short-circuit, output overvoltage, output over-current and current-sense-resistor-short fault protection.