Analog Devices Inc./Maxim Integrated MAX4535CUD

Overview

MAX4535CUD from Maxim Integrated is a dual 2-to-1 fault-protected analog multiplexer with ±4.5V to ±20V dual-supply operation or +9V to +36V single-supply support, 400Ω max on-resistance, ±40V fault protection with supplies off, and rail-to-rail signal handling. It routes high-voltage sensor or actuator signals in industrial control systems where overvoltage transients are common.

For engineers reviewing the MAX4535CUD datasheet, MAX4535CUD pinout, MAX4535CUD application, or MAX4535CUD equivalent, key selection criteria include fault response time (20ns typ), output clamping behavior during overvoltage, TTL/CMOS-compatible logic inputs, and dual-channel independent enable/control for redundant signal paths.

Technical Context

The MAX4535CUD implements dual independent 2-to-1 multiplexers using parallel N- and P-channel FETs per channel to achieve low on-resistance and rail-to-rail conduction. Each NO_ input features dedicated comparators that detect excursions beyond V+ or V− by ~150mV, triggering immediate FET turn-off and COM_ clamping via booster FETs.

Fault protection operates without power sequencing: with supplies off, NO_ pins present virtual open circuits up to ±40V; with ±15V supplies on, fault tolerance is ±25V. COM_ pins are not fault-protected and must remain within supply rails to avoid ESD diode conduction.

Key Specifications

Pinout & Package

MAX4535CUD is housed in a 14-pin TSSOP package (4.4mm × 5mm, 0.65mm pitch), optimized for high-density industrial PCB layouts while maintaining thermal performance up to +70°C ambient.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual 2-to-1 analog multiplexer applications.

Compared with ADG5234BRUZ and TMUX6234RTER, MAX4535CUD uniquely supports true bipolar operation, delivers faster fault response, and guarantees rail-to-rail clamping - making it the only choice for safety-critical, mixed-supply, high-transient environments.

Availability

MAX4535CUD is available at Aetrix Electronics and suitable for industrial data acquisition, avionics sensor routing, and process control I/O modules requiring stable component supply across extended temperature and voltage ranges.

Supply support for MAX4535CUD 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 high-reliability interface ICs for demanding industrial, automotive, and aerospace applications.

The MAX4535CUD belongs to Maxim's fault-protected analog switch family, engineered specifically for high-voltage signal routing in harsh environments where transient immunity and supply flexibility are mandatory.

FAQ

What is the maximum allowable voltage on NO_ pins of the MAX4535CUD when supplies are powered off?

The MAX4535CUD supports ±40V on NO_ pins with supplies off, verified per Absolute Maximum Ratings. This enables safe connection to field wiring during maintenance or brownout conditions without risk of damage. The device presents a high-impedance state on NO_ pins under these conditions, isolating downstream circuitry. Always ensure COM_ remains within V− to V+ even during fault events to prevent ESD diode conduction.

Does the MAX4535CUD require power-supply sequencing during startup?

No, the MAX4535CUD does not require power-supply sequencing. Its internal architecture allows V+ and V− to be applied in any order, and the device enters a known safe state (all channels off) regardless of ramp timing. This eliminates need for external sequencing controllers in multi-rail systems. The MAX4535CUD also remains functional if one supply is missing, provided the other stays within absolute maximum limits.

Can COMA and COMB pins be connected to voltages outside the V+ and V− rails?

No - COMA and COMB pins are not fault-protected. Exceeding V− or V+ on either COM pin forward-biases internal ESD diodes, risking permanent damage. The MAX4535CUD datasheet explicitly states COM pins must remain within supply rails under all operating and fault conditions. For applications requiring extended COM range, external clamping or isolation is mandatory.

What is the typical on-resistance matching between channels in the MAX4535CUD?

The MAX4535CUD guarantees ≤10Ω on-resistance mismatch (∆RON) between channels at TA = +25°C, with typical value of 2Ω. This tight matching ensures consistent gain and offset across dual signal paths - critical for differential measurements or channel-swapping calibration routines. Mismatch remains stable over temperature, supporting accurate ratiometric sensing in industrial environments.

How does the MAX4535CUD behave during a positive overvoltage fault on NO1A?

When NO1A exceeds V+ by ~150mV, the internal positive fault comparator triggers, turning off N1 and P1 FETs to isolate NO1A. If the channel is enabled, P2 activates to clamp COMA to V+, limiting output excursion. Recovery takes ~2.5µs after fault removal. This behavior is identical for all NO_ pins and is fully characterized in the MAX4535CUD datasheet Figures 9 and 17.