VISUAL SOLUTIONS

Crosspoint Switch Ensures Black-Level Accuracy in Composite Video

Intersil’s ISL59530 16 x 16 video crosspoint switch integrates a DC-restore clamp on each video input, achieving consistent black-level accuracy throughout all regions of composite video signals with fewer external components. The overall result is improved picture quality; and cost and board space savings.

The DC-restore clamp biases composite (NTSC and PAL) video by automatically adjusting the DC level of the most negative portion of the video to VREF. The device therefore maintains proper video levels for better picture quality, and allows less fluctuation, eliminating pictures that are too dark or too light. The DC-restore feature can be disabled by the user through an SPI/QSPI-compatible, three-wire serial interface for S-video and component video applications.



The ISL59530’s 16 video inputs and 16 video outputs are non-blocking, allowing users to route any input signal to any output. The device also features a broadcast mode in which any single input can be simultaneously sent to all outputs. With 150MHz of bandwidth in broadcast mode, the ISL59530 is well suited for KVM (Keyboard, Video and Mouse) applications. Outputs can be individually programmed to gains of x1 or x2 for greater flexibility.

The new switch features a -3dB signal bandwidth of 300MHz and a 6MHz signal crosstalk of -90dB. This performance accommodates increasingly high video resolution and provides superior isolation and less leakage between video channels. The device also has a large output current for driving multiple video loads. Each output of the ISL59530 can be put into a high impedance state so that several outputs can be connected together, enabling much larger video matrices without adding rows of buffers.

The chip offers an integrated, fast OSD (On-Screen Display) switch in each output to enable users to switch other graphics – such as the location of the camera providing the video feed – into the video signal. This facility performs at the speeds necessary for ‘glitchless OSD’ or video signal switching without any noticeable smudging, and further reduces the BOM when compared to competing solutions.

The ISL59530 is part of Intersil’s new line of video crosspoint switches that are footprint-compatible with the company’s industry-leading, single-chip 32 x 32 video device. Able to operate from a single 5V supply, it is available in a RoHS-compliant 356-lead BGA package.

Features

• 300MHz non-blocking 16 x 16 video crosspoint switch
• 0.025% differential gain
• 0.05° differential phase
• Output gain switchable x1 or x2 for each channel
• Broadcast mode
• DC-restore clamp
• Individual outputs can be put in a high impedance state
• -90dB isolation at 6MHz
• 0.1dB flatness out to 50MHz
• SPI digital interface
• Single 5V supply operation
• 356-lead RoHS-compliant BGA package

Applications

• Security camera switching
• RGB routing
• HDTV routing

For further information, including the ISL59530 Datasheet and Intersil Product Catalogue on CD ROM, please click here.