Analog Devices Inc./Maxim Integrated MAX367CWN

Overview

MAX367CWN from Maxim Integrated is an 8-channel, two-terminal analog signal-line circuit protector IC designed for series insertion in sensitive analog interfaces. It provides ±40V overvoltage protection, maintains <100Ω on-resistance with power applied, and exhibits <1nA leakage at +25°C - enabling robust protection of op-amps, ADCs, and voltage references in process control and data-acquisition systems.

For engineers reviewing the MAX367CWN datasheet, MAX367CWN pinout, MAX367CWN application, or MAX367CWN equivalent, this device delivers automatic, zero-configuration fault limiting for bipolar (±2.25V to ±18V) or unipolar (4.5V to 36V) supplies - critical when evaluating signal integrity, fault knee voltage (≈1.3V below V+, ≈2.0V above V−), and high-impedance load compatibility.

Technical Context

The MAX367CWN integrates eight independent, symmetrical MOSFET-based protectors per package, each composed of two N-channel and one P-channel enhancement-mode FETs. Its operation relies on gate-threshold–driven conduction: Q1/Q3 turn on when source is ≥1.3V below V+, Q2 turns on when source is ≥2.0V above V− - establishing a low-impedance path only within safe signal bounds.

During fault conditions - defined as any signal voltage within ~1.5V of either supply rail or exceeding it - internal FETs transition into high-impedance state, clamping output to the fault knee voltage without polarity reversal or glitching. No current flows through V+/V− pins during faults; all fault current passes directly between IN/OUT terminals.

Key Specifications

Pinout & Package

MAX367CWN is housed in an 18-pin Wide SO (Small Outline) package, 0.300" body width, with standard 1.27mm pitch. Pin 1 is located at the top-left corner (notch or dot side), and the package is RoHS-compliant per Maxim's 1994 specification.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar analog signal-line protection applications.

Compared with MAX367EWN, the MAX367CWN trades extended temperature capability for lower cost and qualification scope - ideal for commercial-grade data loggers and test equipment. Against MAX366CWN, it delivers 2.7× more protection channels per package, reducing PCB real estate and assembly steps without compromising per-channel performance.

Availability

MAX367CWN is available at Aetrix Electronics and suitable for process control systems, redundant backup systems, and data-acquisition systems requiring stable component supply across multi-year production cycles and legacy design refreshes.

Supply support for MAX367CWN 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 fabless semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and computing applications.

The MAX366/MAX367 product line was engineered specifically to replace discrete shunt-diode networks in analog signal-path protection - delivering automatic, zero-configuration overvoltage limiting with guaranteed leakage, on-resistance, and fault knee behavior across temperature.

FAQ

What is the maximum continuous fault current the MAX367CWN can safely handle?

The MAX367CWN is rated for ≤30mA continuous current into any terminal under fault conditions. Exceeding this limit risks permanent damage. The actual fault current depends on output load resistance and supply voltage - for example, with ±15V supplies and a grounded 1kΩ load, positive-fault current approximates (V+ − 1.3V) ÷ ROUT. Always verify worst-case dissipation against the 762mW limit for its 18-pin Wide SO package.

Can the MAX367CWN be used with single-supply operation, and what are the limitations?

Yes, the MAX367CWN supports unipolar supplies from 4.5V to 36V. However, signals near ground (0V to ~2V) trigger a fault condition, so true 0V-referenced signals require careful termination. With V− tied to ground, the negative fault knee disappears, but the positive knee remains at V+ −1.3V. For ground-referenced systems, ensure signal swing stays above ~2V or use a small negative bias on V− to restore symmetric clamping.

Does the MAX367CWN require external components like pull-up resistors or decoupling capacitors?

No - the MAX367CWN operates autonomously with only V+ and V− connections. No control lines, programming pins, or external biasing are needed. While local 0.1µF ceramic decoupling on V+/V− is recommended for noise immunity, it is not required for basic protection functionality. The device draws <1µA quiescent current, eliminating need for power sequencing.

How does the MAX367CWN behave during power-up and power-down transitions?

During power ramp-up, the MAX367CWN remains in high-impedance (open-circuit) state until V+ and V− reach sufficient threshold to bias internal FET gates - typically >3.5V total supply. Output follows input only after supply stabilizes. During power-down, it reverts to open-circuit before supply collapses, preventing backfeed. This behavior ensures glitch-free signal handover in hot-insertion and brownout scenarios.

Is the MAX367CWN pin-compatible with other members of the MAX366/MAX367 family?

Yes - the MAX367CWN shares identical pinout and footprint with MAX367EWN and MAX367MJN (18-pin Wide SO variant). It is not pin-compatible with the 8-pin MAX366 variants (e.g., MAX366CPA), nor with CERDIP or DIP packages. All MAX367 versions maintain the same 1–3 / 4–8 / 9 / 10–14 / 15–17 / 18 pin mapping and electrical interface.