325 MHz, 8 x 8 Buffered Video Crosspoint Switch (Gain = 2)

The AD8108/AD8109 are high speed 8 × 8 video crosspoint switch matrices. They offer a −3 dB signal bandwidth greater than 250 MHz and channel switch times of less than 25 ns with 1% settling. With −83 dB of crosstalk and −98 dB isolation (at 5 MHz), the AD8108/AD8109 are useful in many high speed applications. The differential gain and differential phase of better than 0.02% and 0.02°, respectively, along with 0.1 dB flatness out to 60 MHz, make the AD8108/AD8109 ideal for video signal switching.

The AD8108 and AD8109 include eight independent output buffers that can be placed into a high impedance state for paralleling crosspoint outputs so that off channels do not load the output bus. The AD8108 has a gain of 1, while the AD8109 offers a gain of 2. They operate on voltage supplies of ±5 V while consuming only 45 mA of idle current. The channel switching is performed via a serial digital control (which can accommodate daisy-chaining of several devices) or via a parallel control allowing updating of an individual output without reprogramming the entire array.

The AD8108/AD8109 is packaged in an 80-lead LQFP and is available over the extended industrial temperature range of −40°C to +85°C.

Applications

* Routing of high speed signals including

* Composite video (NTSC, PAL, S, SECAM)

* Component video (YUV, RGB)\

* Compressed video (MPEG, Wavelet)

* 3-level digital video (HDB3)

* 8 × 8 high speed nonblocking switch arrays: G = 2

* Serial or parallel programming of switch array

* Serial data out allows daisy-chaining of multiple 8 × 8 arrays to create larger switch arrays

* Output disable allows connection of multiple devices

* Pin-compatible with AD8110/AD8111 16 × 8 switch arrays

* For 16 × 16 arrays see AD8116

* Complete solution

* Buffered inputs

* Eight output amplifiers: G = 2

* Drives 150 Ω loads

* Excellent video performance

* 60 MHz 0.1 dB gain flatness

* 0.02%/0.02° differential gain/differential phase error (RL = 150 Ω)

* Excellent ac performance

* −3 dB bandwidth: 250 MHz

* Slew rate: 480 V/µs

* Low power of 45 mA

* Low all hostile crosstalk of −83 dB at 5 MHz

* Reset pin allows disabling of all outputs (connected through a capacitor to ground provides power-on reset capability)

* Excellent ESD rating: exceeds 4000 V human body model

* 80-lead LQFP (12 mm × 12 mm)