Power Integrations' new LinkSwitch-II exceeds global energy-efficiency standards

Power Integrations has launched its LinkSwitch-II family of highly integrated AC-DC switched-mode power conversion ICs with very accurate primary-side control. LinkSwitch-II dramatically simplifies constant-voltage, constant-current (CV/CC) converters, and enables consumer products to meet all worldwide energy-efficiency and no-load regulations, such as ENERGY STAR 2.0 for external power supplies. The new ICs are ideal for applications such as chargers for cell phones and cordless phones, high brightness LED drivers and other accurate CV or CC applications.

LinkSwitch-II, a new generation in Power Integrations' extremely successful LinkSwitch series of ICs, simplifies the design of accurate output CV/CC converters by eliminating the need for optocouplers and all secondary-side CV/CC control circuitry as well as all control-loop compensation circuitry. By integrating all control and protection circuitry plus a 700 V MOSFET in an 8-pin package, LinkSwitch-II significantly reduces component count, space and system cost while increasing reliability. Output CV/CC tolerances of +/-5% and +/-10% respectively are achieved over a 0 - 100 degrees C temperature range by incorporating precision-enhancing features that compensate for transformer inductance tolerances, input line variations, output cable voltage drop (LNK61x only) and external component temperature variations. LinkSwitch-II also offers frequency jittering to greatly reduce EMI filter costs. Sophisticated protection and safety features include auto-restart output short circuit protection and hysteretic thermal shutdown. IEC 60950-1 HV creepage requirements between Drain and all other pins are met and all single point failures are handled safely.

In an example cellphone charger design of 5V/1A, 5 W, LinkSwitch-II offers a simple path to ENERGY STAR EPS 2.0 compliance by achieving average efficiency levels of up to 75% at 25%, 50%, 75% and 100% loads across a 115 to 230 VAC input range. The On/Off control scheme employed in LinkSwitch-II, coupled with low IC power consumption and elimination of secondary-side current sense resistor and control circuitry, provides practically constant efficiency across the entire load range and a no-load consumption of under 30 mW.

Further underlining LinkSwitch-II's green credentials, all family members are produced in halogen-free, RoHS-compliant packaging, which is increasingly being demanded by end customers such as Apple, Nokia Samsung and LG.

Power Integrations