Analog Devices Inc./Maxim Integrated MAX4521ESE

Overview

MAX4521ESE from Maxim Integrated is a quad, low-voltage, normally closed (NC) SPST analog switch IC designed for precision signal routing in rail-to-rail analog paths. It features 100Ω max on-resistance, 4Ω max channel-to-channel on-resistance matching, and 12Ω max on-resistance flatness over ±4.5V signal range. Each switch supports dual supplies (±2V to ±6V) or single +2.7V–+12V operation and delivers <1µW power consumption - ideal for battery-powered data acquisition front-ends.

For engineers reviewing the MAX4521ESE datasheet, MAX4521ESE pinout, MAX4521ESE application, or MAX4521ESE equivalent, key selection criteria include NC configuration, -40°C to +85°C industrial temperature rating, SO-16 narrow-body package, rail-to-rail signal handling capability, and TTL/CMOS-compatible logic thresholds at +5V supply.

Technical Context

The MAX4521ESE implements four independent CMOS transmission gates with complementary N- and P-channel MOSFETs per switch, driven by level-shifted logic to V+ and V−. Its internal architecture enables true bidirectional analog conduction with no ground reference required for signal paths.

All four switches are normally closed (NC), meaning logic-low input maintains continuity between COM and NC terminals, while logic-high opens the path. Input logic thresholds (0.8V low / 2.4V high) ensure compatibility with TTL and CMOS systems operating at ±5V or single +5V supply.

Key Specifications

Pinout & Package

MAX4521ESE is housed in a 16-pin narrow SO (SOIC-N) package (S16-2), 3.9mm × 9.9mm body, 1.27mm pitch, with gull-wing leads and exposed pad not present (QFN variant has EP; SO does not).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX4522ESE and ADG1412BRUZ, the MAX4521ESE uniquely combines NC default state, <1µW quiescent power, and −40°C to +85°C industrial rating - making it optimal for battery-constrained, fail-safe analog routing where continuity at power-up is mandatory.

Availability

MAX4521ESE is available at Aetrix Electronics and suitable for battery-operated equipment, avionics signal conditioning, and automated test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX4521ESE 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 consumer markets.

The MAX4521/MAX4522/MAX4523 family was engineered for low-voltage, low-leakage analog signal routing in space-constrained, power-sensitive systems - emphasizing rail-to-rail operation, precise channel matching, and robust ESD tolerance.

FAQ

What is the default switch state of the MAX4521ESE?

The MAX4521ESE features four normally closed (NC) SPST switches. When all IN1–IN4 inputs are held at logic-low (≤0.8V), each COM–NC path remains conductive. Applying logic-high (≥2.4V) to any IN pin opens that specific switch. This NC behavior ensures signal continuity during system power-up or controller initialization - a key safety feature in MAX4521ESE-based designs.

Can the MAX4521ESE operate from a single +3.3V supply?

Yes, the MAX4521ESE is fully specified for single +2.7V operation. At +3.3V supply (V+ = +3.3V, V− = GND), typical on-resistance is 260Ω, turn-on time is 250ns, and logic thresholds remain compatible (VIN_L = 0.8V, VIN_H = 2.4V). The device maintains rail-to-rail analog range (0V to +3.3V) and <10nA off-leakage at +85°C - confirming reliable function in modern 3.3V embedded systems.

Does the MAX4521ESE require external ESD protection?

No. The MAX4521ESE integrates >2kV ESD protection per Method 3015.7 on all analog and digital pins. Internal diodes clamp transients between signal pins and V+/V−/GND. This built-in protection eliminates the need for discrete TVS devices in most board-level ESD environments (IEC 61000-4-2 Level 2), simplifying layout and reducing BOM count for MAX4521ESE implementations.

How does the MAX4521ESE handle analog signals exceeding the supply rails?

The MAX4521ESE contains internal ESD diodes between each analog pin (COM, NC, NO) and both V+ and V−. If an analog signal exceeds V+ or falls below V−, the corresponding diode conducts, clamping the voltage. To avoid damage, forward diode current must be limited to ±10mA continuous or ±20mA peak (1ms, 10% duty cycle) - a constraint explicitly defined in the MAX4521ESE absolute maximum ratings table.

Is the MAX4521ESE pin-compatible with the DG211 series?

Yes, the MAX4521ESE is explicitly documented as pin-compatible with the industry-standard DG211, DG212, and DG213 analog switches. Pin assignments for COM, IN, NC/NO, V+, V−, and GND match exactly in the 16-pin SO package. This allows direct substitution in existing DG211-based layouts without PCB modification - preserving mechanical fit, thermal profile, and signal integrity in MAX4521ESE retrofits.