Power Integrations' new LinkSwitch-4 switching IC meets U.S. DoE-6 and EU CoC efficiency standards

     Power Integrations, the industry leader in high-voltage integrated circuits for energy-efficient power conversion, has announced the LinkSwitch™-4 family of constant voltage/constant current Primary Side regulation (PSR) switching ics. The LinkSwitch-4 product family uses advanced adaptive base-emitter switch drive technology to support the use of bipolar junction transistor (BJT) switches, dramatically improving power conversion efficiency and eliminating reliability issues from secondary breakdown.

     The new family of devices is specifically designed for chargers and adapters that are required to meet stringent new efficiency standards from the U.S. Department of Energy (DoE) and the European Union Code of Conduct (CoC), both of which are scheduled to go into effect in January 2016. The new DoE standard is DOE-6, which requires efficiency compliance measurement at the end of the charger USB cable; The LinkSwitch-4 exceeds this requirement while using the low complexity Schottky diode secondary, and can even be used for 1.5A and 2A high current smartphone chargers.

     The LinkSwitch-4 IC integrates a multi-mode PWM/PFM controller with a quasi-resonant switching strategy to improve efficiency and meet the requirements of the &lt. 30 mW of no-load power consumption is required while still providing fast transient response. The high operating frequency of 65 kHz can reduce the size of the transformer, and the minimum peak current can be fixed to improve the transient load response speed. The new device compensates for a number of factors, including: transformer inductance tolerances, input voltage variations, cable voltage drops, and peripheral component temperature variations. Very precise IC parameter tolerances are maintained with unique adjustment techniques.

     Mike Matthews, vice president of product development at Power Integrations, said: "The adaptive basebase-emitter switch drive technology used in the LinkSwitch-4 controller improves switching performance and provides higher efficiency than existing BJT or MOSFET switches. The technology also eliminates secondary breakdown associated with BJTS and reduces sensitivity to changes in current gain, allowing the use of BJTS at very low cost. "Adaptive basebase-emitter switch drive technology not only provides flexibility in the selection of BJT transistors during design and manufacturing by significantly optimizing the BJT switching characteristics, but also greatly improves the reliability of BJt-based solutions."