Low-Cost 4x4, 8x4, 8x8 Video Crosspoint Switches

The MAX4359/MAX4360/MAX4456 low-cost video crosspoint switches are designed to reduce component count, board space, design time, and system cost. Each contains a matrix of T-switches that connect any of their four (MAX4359) or eight (MAX4360/MAX4456) video inputs to any of their buffered outputs, in any combination. Each matrix output is buffered by an internal, high-speed (250V/µs), unity-gain amplifier that is capable of driving 400Ω and 20pF at 2.6VP-P. For applications requiring increased drive capability, buffer the MAX4359/MAX4360/MAX4456 outputs with the MAX4395 quad, operational amplifier.

The MAX4456 has a digitally controlled 8x8 switch matrix and is a low-cost pin-for-pin compatible alternative to the popular MAX456. The MAX4359/MAX4360 are similar to the MAX4456, with the 8x8 switch matrix replaced by a 4x4 (MAX4359) or an 8x4 (MAX4360) switch matrix.

Three-state output capability and internal, programmable active loads make it feasible to parallel multiple devices to form larger switch arrays. The inputs and outputs are on opposite sides, and a quiet power supply or digital input line separates each channel, which reduces crosstalk to -70dB at 5MHz. For applications demanding better DC specifications, see the MAX456 8x8 video crosspoint switch.

Applications

* High-Speed Signal Routing * Security Systems * Video Conferencing * Video Test Equipment * Video-on-Demand Systems

* Eight (MAX4456) or Four (MAX4359/MAX4360) Internal Buffers

* 250V/µs Slew Rate

* Three-State Output Capability

* Power-Saving Disable Feature

* 65MHz -3dB Bandwidth

* Routes Any Input Channel to Any Output Channel

* Serial or Parallel Digital Interface

* Expandable for Larger Switch Matrices

* 80dB All-Channel Off-Isolation at 5MHz

* 70dB Single-Channel Crosstalk

* Straight-Through Pinouts Simplify Layout

* Low-Cost Pin-Compatible Alternative to MAX456 (MAX4456)