LCD TV design is separated into three segments: Main Circuit Board, Backlight Inverter, and Power Supply. The Main Circuit Board segment involves hardware device and power sources. For power sources, using a switching mode is an excellent way to improve converter efficiency. High current is its key feature. Power sources that use this technology include system power, power switching, and Class D audio amplification. Low-dropout linear power is another solution for converter efficiency. Its main benefits are low prices and simple circuitry. Hardware can be regarded as a non-power segment. Type of hardware includes remote controls, sensors, and interface protection devices. Some of these need similar functions, such as ESD protection, current limiting, and load switching. The Backlight Inverter segment includes lighting igniters, protection devices, and MOSFET drivers. For lighting igniters, high voltage is a key design concern. Ceramic disc capacitors can meet 6 kV and provide good decoupling. The Power Supply segment involves open-frame switching mode power supplies. Components for primary AC applications include EMI filters, bridge rectifiers, buck capacitors, and PFC rectifiers. The most important design concept is PFC, which involves efficiency improvement. When a PFC rectifier performs well, the power supply can be efficient at a light current load. Regarding secondary side design, the output rectifier is the most important device, especially for multi-output of power supplies. The Trench MOS Schottky rectifier features both high current capabilities and good forward voltage performance at high ambient temperatures. Different solutions are based on different specifications.
A portable media player, or PMP, is a device that is capable of storing and playing digital media, such as audio, images, and video. Some players include the ability to record audio, with a built-in microphone, line-out cable, or FM tuner. PMPs come with either flash or hard disk storage, with several players supporting memory card slots, including slots for CompactFlash (CF), Secure Digital (SD), and memory sticks. In addition to USB connectivity, many players also offer Bluetooth and/or Wi-Fi. Most PMP circuits include some or all of the system blocks shown above.
