Analog Devices Inc./Maxim Integrated MAX378CWG+T

Overview

MAX378CWG+T from Maxim Integrated is an 8-channel single-ended analog multiplexer with series N-channel/P-channel/N-channel fault protection architecture, ±60V continuous input tolerance with ±15V supplies, <2mW power dissipation, and guaranteed break-before-make switching. It serves as a high-reliability signal routing device in data acquisition front-ends where sensor overvoltage and power-loss scenarios must be mitigated without external protection circuitry.

For engineers reviewing the MAX378CWG+T datasheet, MAX378CWG+T pinout, MAX378CWG+T application, or MAX378CWG+T equivalent, this device is selected for industrial sensor interfacing, avionics test equipment, and high-voltage process control systems requiring sub-µA leakage under fault conditions, TTL/CMOS-compatible digital control, and robust ±75V fault tolerance with power supplies off.

Technical Context

The MAX378CWG+T implements a three-FET series switch structure (N-P-N) that actively blocks fault currents by turning off at least one transistor under overvoltage-whether input exceeds +13.5V or falls below –12V with ±15V supplies, or across ±75V when unpowered. This architecture ensures nanoamp-level leakage (<100nA) and prevents latchup even during sustained ±60V analog faults.

Digital inputs operate with fixed 0.8V/2.4V logic thresholds independent of supply voltage, enabling direct TTL/CMOS interface without pull-ups. Break-before-make timing is guaranteed at 25–200ns, and enable-controlled channel selection supports both multiplexing and demultiplexing modes while maintaining full fault isolation in either direction.

Key Specifications

Pinout & Package

MAX378CWG+T is housed in a 24-pin wide SOIC (Small Outline Integrated Circuit) package, 0.300-inch body width, with exposed pad not present. Pin 1 is marked via notch or dot; pin numbering follows standard SOIC convention (counterclockwise from top-left corner).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar analog multiplexer applications.

Compared with ADG508FBRZ and TMUX1308PWR, the MAX378CWG+T uniquely delivers guaranteed nanoamp leakage at ±75V with supplies off, automatic channel disable on power loss, and ±60V continuous fault tolerance-making it the sole option for mission-critical industrial and aerospace signal routing where sensor integrity must be preserved under all failure modes.

Availability

MAX378CWG+T is available at Aetrix Electronics and suitable for industrial process monitoring, avionics test equipment, and high-voltage sensor interface applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing from authorized channels.

Supply support for MAX378CWG+T 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) designs high-performance analog and mixed-signal ICs for demanding industrial, automotive, and communications applications, with emphasis on fault resilience and signal integrity.

The MAX378CWG+T belongs to Maxim's fault-protected analog switch family, engineered specifically for data acquisition and test equipment where sensor overvoltage, power interruption, and channel crosstalk must be eliminated without external protection components.

FAQ

What is the maximum continuous analog input voltage the MAX378CWG+T supports with power supplies active?

The MAX378CWG+T supports ±60V continuous analog input voltage when powered by ±15V supplies. With other supply voltages (±4.5V to ±18V), the rated continuous fault voltage remains ±60V, verified per Absolute Maximum Ratings and Electrical Characteristics tables. Operation beyond ±60V is only guaranteed under unpowered conditions (±75V). The MAX378CWG+T must not be subjected to sustained analog inputs exceeding ±60V while V+ and V− are applied.

Does the MAX378CWG+T require external pull-up resistors on its address or enable pins?

No, the MAX378CWG+T does not require external pull-up resistors. Its digital inputs (A0, A1, A2, EN) have fixed TTL/CMOS-compatible thresholds (0.8V low, 2.4V high) and draw less than 1µA leakage across all logic states. This allows direct connection to microcontroller GPIOs or FPGA outputs without additional components. The MAX378CWG+T maintains these thresholds across its full ±4.5V to ±18V supply range.

How does the MAX378CWG+T behave when power supplies are removed while analog signals remain present?

When V+ and V− are removed, all internal switches turn OFF automatically, and input leakage drops to ≤100nA-even with ±75V applied to any INx or OUT pin. This behavior protects upstream sensors and downstream circuitry from damage or unintended current flow. The MAX378CWG+T achieves this via its series N-P-N FET structure, where gate bias collapse forces conduction cutoff. No external supervision circuitry is needed.

Can the MAX378CWG+T be used as a demultiplexer?

Yes, the MAX378CWG+T functions bidirectionally and supports demultiplexer operation: apply the signal to OUT and route it to one of IN1–IN8 using A0–A2 and EN. It retains guaranteed break-before-make timing and full fault protection-including ±60V tolerance and nanoamp leakage-even in demux mode. Unlike earlier fault-protected muxes, the MAX378CWG+T provides identical protection characteristics regardless of signal direction.

What is the typical ON-resistance matching between channels of the MAX378CWG+T?

At +25°C with ±15V supplies and ±10V analog input, R_DS(ON) matching is ±2% across all eight channels (lowest to highest). At –10V input, matching degrades slightly to ±3%. This tight matching ensures consistent gain and minimal channel-to-channel error in precision gain-setting or calibration applications. The MAX378CWG+T datasheet specifies R_DS(ON) as 2.0kΩ max, with typical value ~1.5kΩ.