Dialog Semiconductor plc claims the world’s first ac-dc rapid charge controller compatible with MediaTek’s new Pump Express™ fast-charge protocol. The iW1680 is a single-chip solution that uses Dialog’s intelligent rapid charge digital algorithm and digital primary-side control technology to significantly reduce charge times in USB ac-dc wall chargers with no bill of materials (BOM) cost premium over slower conventional charging technologies. “Pump Express” is MediaTek’s proprietary protocol for fast charging mobile devices, including feature phones, smartphones and media tablets, up to 45 percent faster than conventional chargers.
"Working closely with MediaTek, we are delighted to introduce the first Pump Express-compatible ac-dc controller and bring our complementary rapid charge technologies to the China market quickly and cost effectively."
Conventional USB chargers provide a fixed 5-volt (V) supply that requires a buck converter inside the handset to convert the 5V down to the required output voltage. The iW1680 uses Dialog’s built-in, intelligent rapid charge digital algorithm that communicates with MediaTek Pump Express-compatible phones and dynamically scales the output voltage of the wall charger to deliver the optimized level required by the phone at any given time. This lowers the overall system cost by eliminating the need for an input buck converter in the phone and reduces charge times by enabling more efficient power transfer to the phone battery.
Building on Dialog’s leadership in accurate primary-side control for ac-dc power supplies with the latest derivative of its PrimAccurate primary-side controller platform, the iW1680 rapid charge ac-dc controller embeds sophisticated digital analysis on the primary side of the isolated power supply within the charger. This allows voltage scaling without the need for any intelligence on the secondary side and further reduces costs.
“Reducing charge time is one of the most compelling trends in smartphones, especially with the rapid and endless surge in ever more power-hungry applications,” said Mark Tyndall, Senior VP Corporate Development & Strategy, GM Power Conversion Business Group at Dialog Semiconductor. “Working closely with MediaTek, we are delighted to introduce the first Pump Express-compatible ac-dc controller and bring our complementary rapid charge technologies to the China market quickly and cost effectively.”
The iW1680 supports power adapters up to 7.5W, with high active average efficiency and low no-load power consumption less than 30mW. Communication between the phone and iW1680 is through the VBUS supply line. Voltage scaling is digitally managed on the primary side of the transformer in the ac-dc adapter by the iW1680, which analyses the signal of the VBUS and scales its output voltage accordingly. The iW1680 easily and efficiently drives low-cost bipolar junction transistor (BJT) switches to further drive down BOM costs and reduce electromagnetic interference (EMI). The iW1680 comes in a 6-pin SOT23 package. Full protection features include built-in output short-circuit, and output overvoltage, output over-current and over-temperature protection.