Fairchild Semiconductor announced that it is bringing power designers of LCD and PDP TVs, servers, game consoles and LED lighting applications the FAN7621 – a resonant controller that is said to simplify design, reduce bill of materials and provide advanced protection functions. The FAN7621 integrates a high-side gate-drive circuit, a current-controlled oscillator, frequency- limit circuit, soft start and numerous protection functions in a 16-pin SOP/DIP package.
According to the company, this highly integrated device eliminates the need for expensive external circuitry such as pulse transformers to conserve not only board space but to reduce the cost of the overall design. The FAN7621’s internal high side gate-drive circuit is said to offer an added benefit of common-mode noise cancellation, and to ensure excellent noise immunity, enabling the application to meet stringent EMI specifications. For further noise immunity, the FAN7621 offers designers a zero voltage switching (ZVS) technique that reduces switching noise and allows the use of a smaller and less expensive EMI filter.
The FAN7621 is designed with robust protection features such as over voltage protection (OVP), over current protection (OCP), abnormal over current protection (AOCP) and internal thermal shutdown. Other solutions require additional components to achieve the same level of protection, which adds to design time and overall system costs.
The FAN7621’s ZVS technique is said to dramatically reduce switching losses in MOSFETs and rectifiers. According to the company, compared to conventional hard-switching converter topologies, efficiency is improved by 10% and for applications such as PDP-TVs, efficiency reaches 97%. An added advantage of this ZVS technique is the dramatic reduction in switching noise – at least 5dB – compared to hard-switching techniques.
The units are priced (each, 1000 pcs) at $0.50 with a delivery of 12 weeks ARO.