Multiplexers transmit quality audio video and high-speed USB

The move to fewer I/O ports is well demonstrated by the recent launch of Apple's iPod Shuffle, which uses a single 1/8 jack for USB and headphone connections. Intersil’s ISL54415/6/7 multiplexers give users the ability to display images on a TV from a portable media player, in addition to providing an audio output, and still using a single I/O port to minimise cost and size.

The multiplexers combine high-speed, low-capacitance switches for data signals with low-distortion, low-capacitance switches for audio and video, so they can be used for data downloading or for A/V playback through a single port without impacting performance in either mode of operation. This increases available board space, reduces external components, and lowers the manufacturing cost of portable devices that need to connect to other equipment such as TVs, flat screen monitors, headphones, speakers and PCs.

The ISL54415/6/7 multiplexers can switch between USB or other digital data and A/V signals in personal media player applications. The family is designed to reduce the number of connectors and cables required to connect Personal Media Players (PMP), Digital Still Cameras (DSC), camcorders and other consumer electronics products to other equipment such as TVs, flat screen monitors and PCs.
Negative signal swing capability on the audio and video inputs of these multiplexers allows these signals to be ac coupled, preventing battery discharge of the portable device if left connected to a powered-down piece of equipment.

Existing solutions rely upon bulky and costly external passive components such as inductors to prevent the A/V signals and the USB data signals from interfering with each other, sometimes resulting in the inability to transmit video signals. The ISL54415/6/7 overcome these problems while consuming very low power in operation.

All three of the multiplexers are available in space-saving micro TQFN 2.1 x 1.6mm x 0.5mm packages. The ISL54415 incorporates the functions needed to detect a USB cable and provides the data speed indicator function for USB data transmission. The ISL54416 detects the USB cable but leaves the USB speed indicator function to users, while the ISL54417 is a basic USB/audio/Video switch without the USB detection capabilities.

Target applications for the multiplexers include digital still cameras, personal media players, analogue and digital camcorders, and audio/video accessories. All three versions of the multiplexers are available in micro TQFN packages, and evaluation boards are also available.