Low-cost USB charger IC for smartphones

September 16, 2013 // By Graham Prophet
Cambridge Semiconductor – CamSemi – has introduced the C2172PX8 PSS controller targeting low cost USB chargers for smartphones and other apps to 7.5W. This is the first in a series of parts that will move the company’s C2170 family into higher powers.

C2170 uses a patented BJT scheme and is delivering what the company believes is the industry’s lowest cost, most energy-efficient BJT-based solutions for mobile phone chargers to 7.5W. The Primary Side Sensing (PSS) C2172PX8 controller targets low cost, MoU-compliant USB chargers for smartphones, tablets and other universal input applications rated to 7.5W, whereas the first two C2170 controllers launched in June are optimised for applications to 4W and 6.5W.

The C2172PX8 controller combines the company’s bipolar transistor (BJT) drive scheme, advanced PSS technology and several power-saving techniques to help manufacturers develop ultra low cost, more energy-efficient BJT-based solutions. These approaches enable simpler circuits with reduced component counts and system costs but with significant performance and manufacturing advantages. CamSemi’s improved drive technology boosts switching performance and delivers higher active mode efficiency, greater product robustness from more Reverse Bias Safe Operating Area (RBSOA) margin and the flexibility to accommodate a wide range of low cost BJTs for further cost savings.

C2172PX8 also offers ‘best in class’ voltage regulation of ±2% and current regulation of ±3% allowing more margin for thermal design; no-load power consumption is well below 30 mW; and IC power consumption and design have been optimised to enable fast start of 500 msec but without needing the extra cost, space and complexity of an active start-up switch. C2172PX8 is packaged in surface mount SOP8

CamSemi; www.camsemi.com/datasheets