Analog Devices Inc./Maxim Integrated MAX312FESE+T

Overview

The MAX312FESE+T from Maxim Integrated is a quad SPST analog switch with normally closed (NC) configuration, fault-protected inputs, rail-to-rail signal handling, 10Ω max on-resistance at ±15V, ±36V fault protection with power on, and operation across ±4.5V to ±20V dual supplies or +9V to +36V single supply - used in industrial signal routing and test equipment where overvoltage resilience is critical.

For engineers reviewing the MAX312FESE+T datasheet, MAX312FESE+T pinout, MAX312FESE+T application, or MAX312FESE+T equivalent, key selection criteria include fault-protection voltage limits, NC vs NO topology, on-resistance matching, leakage current under fault conditions, and compatibility with TTL/CMOS logic at ±15V or +12V supply.

Technical Context

The MAX312FESE+T implements dual-FET (N+P channel) parallel switching per channel to achieve low R_ON and true rail-to-rail conduction. Its internal comparators continuously monitor COM_, NO_, and NC_ terminals against V+ and V−, forcing high-impedance isolation within 600ns when signals exceed ±36V (power on) or ±40V (power off).

All four switches are NC type and share identical pinout with industry-standard DG411. Control logic thresholds (+0.8V/2.4V) ensure interoperability with TTL and CMOS drivers under ±15V or +12V supply, and no power-supply sequencing is required - V+ can be unpowered while V− remains active without compromising switch-off integrity.

Key Specifications

Pinout & Package

MAX312FESE+T is housed in a 16-pin SOIC (SO) package with 1.27mm pitch, JEDEC MS-012AC compliant, and rated for -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX313FESE+T (NO default) and ADG411BRZ (no fault protection), the MAX312FESE+T uniquely delivers NC fail-safe behavior plus integrated ±40V fault tolerance - eliminating both external protection components and safety-critical firmware dependencies in industrial and avionics signal paths.

Availability

MAX312FESE+T is available at Aetrix Electronics and suitable for industrial signal routing, automated test equipment, data acquisition systems, and avionics redundancy switching requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX312FESE+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 precision analog, mixed-signal, and power management ICs for demanding industrial, automotive, and communications applications.

The MAX312F series belongs to Maxim's fault-protected analog switch product line, engineered specifically for high-reliability signal routing in environments prone to wiring errors, ESD, and power rail transients.

FAQ

What is the default switch state of MAX312FESE+T?

The MAX312FESE+T features four normally closed (NC) SPST switches. When logic inputs IN1–IN4 are low (≤0.8V), the corresponding NC-to-COM paths conduct. When inputs go high (≥2.4V), those paths open. This NC default ensures signal continuity during power-up, reset, or controller failure - a critical safety feature in industrial and avionics systems where uninterrupted signal flow is required. The MAX312FESE+T maintains this behavior across its full operating temperature range (-40°C to +85°C).

Does MAX312FESE+T require power-supply sequencing?

No, MAX312FESE+T does not require power-supply sequencing. It remains safely off even when V+ is unpowered while V− remains active - a key reliability feature confirmed in the datasheet's "All Switches Off when V+ is Off and V− is On" specification. This eliminates timing constraints during system power-up/down and prevents unintended conduction during brownout conditions. The MAX312FESE+T achieves this via independent comparator-based fault detection and gate-drive architecture that functions regardless of V+ presence, making it robust in multi-rail industrial power architectures.

What is the maximum fault voltage MAX312FESE+T can withstand with power off?

The MAX312FESE+T withstands up to ±40V on COM_, NC_, and NO_ terminals when all supplies are removed - explicitly stated in the Absolute Maximum Ratings and Features sections. This exceeds the ±36V rating with power applied and enables safe handling of disconnected field wiring or accidental contact with higher-voltage systems during maintenance. The protection is inherent to the device's internal FET structure and requires no external components. This ±40V-with-power-off rating is a defining characteristic of the MAX312FESE+T and is validated across the full -40°C to +85°C temperature range.

Can MAX312FESE+T operate from a single +12V supply?

Yes, MAX312FESE+T operates from a single +12V supply by connecting V− to GND. In this configuration, it supports analog signals from 0V to +12V (rail-to-rail), maintains 30Ω max R_ON, and retains ±36V fault protection (with power on) and ±40V protection (with power off). Logic inputs remain TTL/CMOS-compatible with +0.8V/2.4V thresholds. The datasheet confirms this mode in the "ELECTRICAL CHARACTERISTICS-Single +12V Supply" table, and the pinout diagram shows V− tied to GND. This flexibility allows the MAX312FESE+T to serve both legacy ±15V and modern +12V industrial platforms without redesign.

Is MAX312FESE+T pin-compatible with DG411?

Yes, MAX312FESE+T is pin-compatible with the industry-standard DG411. The datasheet explicitly states "pin compatible with industry-standard DG411/DG412/DG413" and provides identical pin numbering and function mapping (e.g., IN1–IN4, COM1–COM4, NC1–NC4, V+, V−, GND, N.C.). This enables direct replacement on existing PCBs without layout changes. However, unlike DG411, the MAX312FESE+T adds integrated fault protection, rail-to-rail operation, and lower on-resistance - delivering enhanced robustness while preserving mechanical and electrical fit.