The MAX456 is the first monolithic CMOS 8 x 8 video crosspoint switch that significantly reduces component count, board space, and cost. The crosspoint switch contains a digitally controlled matrix of 64 T-switches that connect eight video input signals to any, or all, output channels. Each matrix output connects to eight internal, high-speed (250V/µs), unity-gain-stable buffers capable of driving 400Ω and 20pF to ±1.3V. For applications requiring increased drive capability, the MAX456 outputs can be connected directly to two MAX470 quad, gain-of-two video buffers, which are capable of driving 75Ω loads. Three-state output capability and internal, programmable active loads make it feasible to parallel multiple MAX456s and form larger switch matrices. In the 40-pin DIP package, crosstalk (70dB at 5MHz) is minimized, and board area and complexity are simplified by using a straight-through pinout. The analog inputs and outputs are on opposite sides, and each channel is separated by a power-supply line or quiet digital logic line.
The MAX456 is the first monolithic CMOS 8 x 8 video crosspoint switch designed to reduce component count, board space, and cost. It contains a digitally controlled matrix of 64 T-switches that connect eight video input signals to any or all output channels. Each matrix output connects to eight internal, high-speed, unity-gain-stable buffers capable of driving 400Ω and 20pF loads.
The device features three-state output capability and internal, programmable active loads, making it feasible to parallel multiple MAX456s to form larger switch matrices. It offers an 80dB all-channel off isolation at 5MHz and includes 8 internal buffers with a 250V/µs slew rate and 35MHz bandwidth. The chip is available in 40-pin DIP, 44-pin PLCC, and dice packages.
| Product Type | 8 x 8 Video Crosspoint Switch |
|---|---|
| Number of Switches | 64 T-switches |
| All-Channel Off Isolation | 80dB at 5MHz |
| Buffer Slew Rate | 250V/µs |
| Bandwidth | 35MHz |
| Supply Voltage Range | +4.5V to +5.5V |
Yes, the MAX456 outputs can be connected directly to two MAX470 quad, gain-of-two video buffers to drive 75Ω loads.
It supports both Serial and Parallel Digital Interface modes for controlling the switch matrix.