Analog Devices Inc./Maxim Integrated MAX367EPN+

Overview

MAX367EPN+ from Maxim Integrated is an 8-channel, two-terminal analog signal-line circuit protector IC designed for series insertion in sensitive analog signal paths. It operates with bipolar supplies (±2.25V to ±18V) or unipolar supplies (4.5V to 36V), delivers ≤100Ω on-resistance with power applied, limits fault current via voltage-dependent high-impedance transition, and protects against ±40V overvoltage transients - used in data-acquisition front-ends, hot-insertion I/O modules, and precision instrument sensor interfaces.

For engineers reviewing the MAX367EPN+ datasheet, MAX367EPN+ pinout, MAX367EPN+ application, or MAX367EPN+ equivalent, this page provides verified technical context, exact pin-to-function mapping for the 18-pin plastic DIP package, confirmed fault knee voltages (≈1.3V below V+, ≈2.0V above V−), leakage <1nA at +25°C, and validated alternatives for industrial-grade signal protection where power-off isolation and rail-clamped fault response are mandatory.

Technical Context

The MAX367EPN+ integrates eight independent, symmetrical two-terminal protectors-each built from three enhancement-mode MOSFETs (two N-channel, one P-channel)-with no control logic or external programming required. Its operation relies entirely on internal gate-threshold biasing relative to V+ and V−, enabling automatic transition between low-resistance conduction (normal signal pass) and high-resistance limiting (fault condition) without timing delays or latch-up risk.

During fault events-defined as any signal voltage within ~1.5V of either supply rail-the device dynamically raises path resistance to limit current while clamping the protected-side output to a predictable "knee" voltage: approximately (V+ − 1.3V) for positive faults and (V− + 2.0V) for negative faults. Critically, zero fault current flows through V+ or V− pins; all fault current passes directly between IN and OUT terminals.

Key Specifications

Pinout & Package

MAX367EPN+ is housed in an 18-pin plastic DIP (dual-in-line package) with 0.300″ body width, rated for −55°C to +125°C operating temperature. Pin 1 is top-left corner when notch faces up; pin numbering proceeds counter-clockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX367EWN+, MAX367EPN+ offers superior mechanical robustness and thermal dissipation in demanding industrial settings; compared with MAX366EPA+, it delivers 2.7× channel density per package-reducing BOM line items, PCB real estate, and interconnect parasitics in 8+ channel analog I/O designs.

Availability

MAX367EPN+ is available at Aetrix Electronics and suitable for process control systems, hot-insertion boards, and data-acquisition systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX367EPN+ 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 family was engineered specifically for fault-tolerant analog signal routing in modular instrumentation-prioritizing rail-clamped overvoltage protection, power-off isolation, and ultra-low leakage over speed or digital control.

FAQ

What is the maximum continuous fault voltage the MAX367EPN+ can withstand with power off?

The MAX367EPN+ sustains ±40V differential between its IN and OUT terminals when V+ = V− = 0V-its highest-rated fault condition. This capability ensures protection during complete system power loss, cable hot-plug events, or brownout scenarios where external voltages may appear before local supplies stabilize. The device remains in high-impedance state with <1000nA leakage under this stress, verified per Absolute Maximum Ratings table.

Does the MAX367EPN+ require external components to function as a signal protector?

No, the MAX367EPN+ requires only V+ and V− supply connections and series placement in the signal path-no external resistors, capacitors, or control signals. Its protection action is fully autonomous, driven by internal MOSFET gate thresholds relative to the applied supplies. This eliminates BOM additions, layout dependencies, and calibration steps required by discrete diode-or resistor-based solutions.

Can the input and output pins of the MAX367EPN+ be swapped in the PCB layout?

Yes, every signal terminal (pins 1–3, 4–8, 10–14, 15–17) on the MAX367EPN+ is functionally identical and bidirectional-labeled IN/OUT only for schematic clarity. The internal protector cell is symmetrical: current flows equally well from IN to OUT or OUT to IN, and fault clamping behavior is identical regardless of signal direction. This simplifies routing and enables reuse of same footprint for input or output protection.

What is the typical on-resistance of the MAX367EPN+ and how does it vary with supply voltage?

The MAX367EPN+ exhibits ≤100Ω typical on-resistance at ±10V supplies, decreasing to ~40Ω at ±15V and increasing to ~150Ω at ±5V-per Typical Operating Characteristics curves. This variation arises from enhanced FET channel conduction at higher gate-source bias. Designers must account for this in precision gain-setting networks, though the effect remains linear and predictable across the specified supply range.

How does the MAX367EPN+ behave during power supply ramp-up and ramp-down sequences?

During V+ and V− ramp-up, the MAX367EPN+ remains in high-impedance fault state until supply voltages exceed the input signal level-then transitions smoothly to low-resistance conduction. During ramp-down, it holds conduction until supplies fall below the signal, then reverts to open-circuit isolation. This behavior prevents signal glitches, backfeeding, or latch-up during controlled power sequencing, as confirmed in the Low-Voltage Operation section of the datasheet.