Valley switching answers Californian concerns

Highly integrated power switch ICs provide high energy efficiency and system reliability in DVD player, set top box, LCD monitor and other 25W and lower power supply designs.

The Green FPS e-Series is a new family of Fairchild Power Switch products that provide high energy efficiency and system reliability in DVD player, set top box, LCD monitor and other 25W and lower power supply designs.

Based on Fairchild's proprietary valley switching technique, the Green FPS products raise power conversion efficiency by 1% and reduce EMI up to 5dB compared with conventional hard-switch convertor topologies.

These highly integrated FPS devices combine the functionality of a fully avalanche rated SenseFET, a current mode pulsewidth modulation (PWM) IC and various protection functions, simplifying design and improving system reliability.

Using advanced burst mode operation, the Green FPS e-Series devices meet standby power regulations by reducing standby power consumption to below 0.2W at no load conditions (below 1W at 0.5W load).

"Fairchild's Green FPS e-Series devices offer designers the advantages of PWM IC and MOSFET integration together with high energy efficiency and reliability in an all-in-one solution, helping them in their never-ending pursuit to meet demanding power consumption and energy regulations affecting today's power supply market", says HK Kim, Fairchild's Vice President of the Power Conversion product line.

"Utilising a proprietary valley switching technique, these products provide the highest levels of efficiency to meet the standards as specified by the California Energy Commission (CEC), EU Code of Conduct, and Group for Energy Efficient Appliances (GEEA)".

By employing an advanced control technique, the Green FPS e-Series products allow power convertors to operate with narrow frequency variation while maintaining valley switching operation.

Valley switching operation enables the MOSFET to turn on with minimum drain voltage and offers inherent frequency modulation resulting in a dramatic reduction in EMI noise up to 5dB compared with conventional hard-switch convertors.

This valley switching operation also enables these convertors to perform soft switching, therefore increasing power conversion efficiency by 1% while drastically reducing heat generation.

Designs employing Green FPS e-Series products provide superior system reliability and space benefits compared with discrete MOSFET/controllers, RCC switching convertors, or conventional hard-switching solutions due to space saving 8-lead DIP and 8-lead LSOP packaging and the inclusion of a variety of protection circuitry.

This circuitry includes overvoltage protection, overload protection, abnormal overcurrent protection and thermal shutdown protection.

Additional features include an integrated fixed oscillator, undervoltage lockout, optimised blanking and gate turn-on/turn-off driver, and temperature compensated precision current sources for loop compensation.

These products meet or exceed the requirements of the joint IPC/JEDEC standard J-STD-020C and are compliant with European Union regulations now in effect.

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