Replaces FETs with lower-cost BJTs at up to 10W

iW1679是高性能AC / DC控制器designed to easily and efficiently drive an external, power bipolar junction transistor (BJT) for peak current mode PWM flyback power supplies rated at up to 10W. It replaces MOSFETs with lower-cost BJTs to reduce the BOM cost in 5V/2A power adapters for smart phones, media tablets and consumer electronic products. Additional BOM cost savings come from Dialog’s patented PrimAccurate™ primary-side control technology that eliminates the need for a secondary-side regulator and optical feedback isolator.

The iW1679 uses digital control technology to actively modulate the BJT base current drive, optimizing performance and improving efficiency by keeping the BJT out of saturation. The device provides high, 83% active average efficiency, maintains high efficiency at loads as light as 10%, and achieves <30mW no-load standby power with fast response to power load changes, easily meeting the US DoE external power supply standard and the EU’s Code of Conduct, version 5, tier 2 standard. In addition to BJTs generating lower EMI compared to FETs, the iW1679 uses Dialog’s EZ-EMI® technology that uses valley mode switching to further reduce EMI and reduce the cost of external filtering components. It also includes a proprietary switching mode that results in no audible noise from the controller.