Analog Devices Inc./Maxim Integrated MAX349EAP

Overview

MAX349EAP from Maxim Integrated is an 8-channel, serially controlled, bidirectional analog multiplexer with SPI/QSPI/MICROWIRE interface, 100Ω max on-resistance (±5V supplies), rail-to-rail signal handling, and -40°C to +85°C industrial temperature range. It operates from ±2.7V to ±8V dual supplies or +2.7V to +16V single supply, and is used in serial data-acquisition systems requiring low-leakage, high-isolation switching.

For engineers reviewing the MAX349EAP datasheet, MAX349EAP pinout, MAX349EAP application, or MAX349EAP equivalent, this page delivers verified specifications, validated pin functions, real-world use scenarios in industrial control and ATE, and two confirmed alternative parts with documented technical and application differences.

Technical Context

The MAX349EAP implements an 8-bit shift register architecture synchronized to SCLK's rising edge, with CS-controlled latching on its rising edge-fully compliant with SPI Mode 0 (CPOL=0, CPHA=0). All eight switches are independently controllable via a single 8-bit serial word, where D7 controls NO0 and D0 controls NO7.

Its analog path supports bidirectional rail-to-rail signals across the full supply range, with matched on-resistance (≤16Ω) and flatness (≤10Ω) over ±3V input range. Off-leakage is specified at 0.1nA @ +25°C and 5nA @ +85°C, enabling precision measurement paths in low-current systems.

Key Specifications

Pinout & Package

MAX349EAP is supplied in a 20-pin SSOP package (body width 0.209", 5.30mm), RoHS-compliant, with exposed pad not internally connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADG1408BRUZ and TMUX1308PWR, MAX349EAP uniquely supports dual ± supplies, includes hardware RESET, and offers SPI/QSPI/MICROWIRE interoperability - making it the only choice for legacy industrial controllers requiring guaranteed power-up safety and multi-standard bus compatibility.

Availability

MAX349EAP is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment (ATE), avionics sensor interfaces, and professional audio routing requiring stable component supply across extended temperature and mixed-supply environments.

Supply support for MAX349EAP 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 MAX349EAP belongs to Maxim's serially controlled analog switch family, engineered specifically for high-reliability, low-leakage, multi-supply multiplexing in data-acquisition and test systems where SPI compatibility and guaranteed power-up state are mandatory.

FAQ

What is the maximum supply voltage range supported by the MAX349EAP?

The MAX349EAP supports dual supplies from ±2.7V to ±8V, or a single supply from +2.7V to +16V. This allows operation in legacy ±5V systems, modern low-voltage designs, and wide-range industrial rails. The absolute maximum ratings specify V+ to -0.3V/+17V and V- to -17V/+0.3V, but functional operation is guaranteed only within the specified ranges. MAX349EAP maintains rail-to-rail signal handling across all supported supply configurations.

Does the MAX349EAP require external pull-up resistors on its digital control pins?

No, the MAX349EAP does not require external pull-ups on DIN, SCLK, CS, or RESET. Its digital inputs have fixed TTL/CMOS-compatible thresholds (0.8V low, 2.4V high) and are designed to interface directly with standard microcontroller GPIOs operating at +5V or ±5V. Internal input current is limited to ±1µA, eliminating need for external biasing. MAX349EAP's RESET pin is active-low and internally weak-pull-up free - system design must drive it explicitly.

How does the MAX349EAP handle power-up initialization?

Upon power-up, the MAX349EAP automatically resets all internal shift registers to zero and turns OFF all eight switches - ensuring a known safe state before firmware intervention. This behavior is guaranteed across the full -40°C to +85°C temperature range and does not depend on external reset circuitry. The MAX349EAP's asynchronous RESET pin provides additional deterministic control, forcing the same zero-state condition regardless of supply ramp timing.

Can the MAX349EAP be daisy-chained with other MAX349EAP or MAX350 devices?

Yes, the MAX349EAP supports daisy-chaining via its DOUT pin, which outputs the shifted-in data delayed by eight clocks. Multiple MAX349EAP or MAX350 devices can share CS and SCLK while connecting DIN → DOUT → DIN in series. When CS rises, all devices simultaneously update their switch states. MAX349EAP's DOUT logic-high level equals V+, so level translation may be required when cascading into 3.3V logic domains.

What is the guaranteed on-resistance match between channels in the MAX349EAP?

The MAX349EAP guarantees ≤16Ω on-resistance match (∆RON = RON_max − RON_min) between any two channels at TA = +25°C with ±5V supplies and VCOM = ±3V. This specification ensures predictable gain tracking in multi-channel instrumentation amplifiers and matched attenuation in programmable filter banks. MAX349EAP's match remains stable over temperature, with typical variation of <5Ω from -40°C to +85°C per characterization data.