Analog Devices Inc./Maxim Integrated MAX456CPL

Overview

MAX456CPL from Maxim Integrated is a monolithic CMOS 8×8 video crosspoint switch with 64 T-switches, eight unity-gain-stable output buffers (250 V/µs slew rate, ±1.3 V swing into 400 Ω), and parallel/serial digital control interface - designed for routing standard composite video signals in test, security, and editing systems.

For engineers reviewing the MAX456CPL datasheet, MAX456CPL pinout, MAX456CPL application, or MAX456CPL equivalent, key selection criteria include off-isolation (80 dB at 5 MHz), crosstalk performance (70 dB single-channel), buffer drive capability, LOAD-pin programmable internal 400 Ω active loads, and compatibility with 75 Ω systems via external MAX470 buffers.

Technical Context

The MAX456CPL implements a two-rank register architecture: first-rank registers accept parallel (7-bit) or serial (32-bit) configuration data, while second-rank registers control the 8×8 analog matrix and buffer enable states. Edge- or level-sensitive LATCH operation allows synchronous or transparent update modes.

Each of the eight output buffers integrates a high-speed amplifier (35 MHz bandwidth), three-state output control, power-saving disable, and programmable internal 400 Ω load activation via the LOAD pin - enabling stable operation without external termination when driving 400 Ω/20 pF loads.

Key Specifications

Pinout & Package

The MAX456CPL is housed in a 40-pin plastic DIP package with straight-through pinout: analog inputs (IN0–IN7) on one side, outputs (OUT0–OUT7) on the opposite side, and digital control lines (A0–A2, D0–D3, WR, LATCH, CE, SER/PAR, EDGE/LEVEL, LOAD) distributed across top/bottom edges - minimizing board-level crosstalk and simplifying layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8×8 video crosspoint switch applications.

Compared with MAX458CPL and AD8175ARZ, the MAX456CPL offers the best balance of analog video fidelity (0.5% differential gain error), low-cost 40-pin DIP packaging, and flexible interface options - making it the go-to solution for cost-sensitive, high-isolation analog video routing where 75 Ω direct drive is not required.

Availability

MAX456CPL is available at Aetrix Electronics and suitable for video test equipment, security system integration, and broadcast editing infrastructure requiring stable component supply across extended production lifecycles.

Supply support for MAX456CPL includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX456 product line was developed specifically for analog video signal routing in professional test, security, and post-production environments - emphasizing high off-isolation, low crosstalk, and robust buffer drive capability in through-hole packages.

FAQ

What is the operating temperature range for the MAX456CPL?

The MAX456CPL is rated for operation from 0°C to +70°C - the 'C' grade designation indicates commercial temperature range. This makes it suitable for indoor video equipment such as studio monitors, security DVR front-ends, and benchtop test instruments where ambient conditions remain controlled. The MAX456CPL does not support extended or automotive temperature ranges; for -40°C to +85°C operation, the MAX456EPL variant must be selected.

How does the LOAD pin affect MAX456CPL buffer stability?

The LOAD pin on the MAX456CPL enables internal 400 Ω active loads on all eight output buffers when driven high (typically +5 V). These loads are mandatory for unity-gain stability - if LOAD is low, external 400 Ω terminations must be added to each output. Failure to provide either internal or external resistive loading causes oscillation or distorted video output. The MAX456CPL datasheet explicitly states "the buffers MUST have a resistive load to maintain stability."

Can the MAX456CPL drive 75 Ω coaxial video lines directly?

No, the MAX456CPL cannot drive 75 Ω coaxial video lines directly. Its output buffers are optimized for 400 Ω loads and ±1.3 V swing. To drive 75 Ω systems, the MAX456CPL outputs must interface with external gain-of-two video buffers such as the MAX470 - which provide proper 75 Ω drive capability, level shifting, and impedance matching. This two-chip solution is documented in the MAX456CPL typical application circuit (Figure 2) and is the recommended implementation for broadcast-quality video distribution.

What is the function of the EDGE/LEVEL pin on the MAX456CPL?

On the MAX456CPL, the EDGE/LEVEL pin determines how the LATCH signal updates the second-rank registers. When EDGE/LEVEL = 5 V, LATCH operates edge-triggered - data transfers on the rising edge. When EDGE/LEVEL = 0 V, LATCH operates level-sensitive - data passes transparently while LATCH is low. This flexibility allows either synchronous (edge) or asynchronous (level) configuration updates, supporting both precise timing control and simple microcontroller GPIO implementations without strict edge alignment requirements.

Does the MAX456CPL include power-on reset functionality?

Yes, the MAX456CPL includes an internal power-on reset (POR) circuit that holds all output buffers disabled for 5 µs after V+ and V− reach valid levels. During this time, the switch matrix retains no defined state - it must be explicitly programmed before enabling any buffers. The POR ensures glitch-free startup by preventing unintended video output transients, but designers must issue initialization commands (e.g., "turn on all buffers" or "connect IN0→OUT0") after the 5 µs window to establish known signal paths.