Analog Devices Inc./Maxim Integrated MAX350CPN+

Overview

MAX350CPN+ from Maxim Integrated is a dual 4-channel serially controlled analog multiplexer, configured as two independent 4-to-1 muxes (COMA/NO0A–NO3A and COMB/NO0B–NO3B), with bidirectional rail-to-rail signal handling, 100Ω max on-resistance at ±5V supplies, and SPI/QSPI/MICROWIRE-compatible 3-wire interface - used in industrial data-acquisition systems for routing multiple sensor signals to a single ADC.

For engineers reviewing the MAX350CPN+ datasheet, MAX350CPN+ pinout, MAX350CPN+ application, or MAX350CPN+ equivalent, key selection criteria include dual independent 4:1 switching architecture, ±2.7V to ±8V dual-supply operation, <0.1nA off-leakage at +25°C, daisy-chainable serial interface, and 18-pin PDIP package compatibility with legacy control systems.

Technical Context

The MAX350CPN+ implements an 8-bit shift register driving two separate 4-switch banks, updated synchronously on the rising edge of CS; each bit controls one NOx switch, enabling arbitrary channel combinations per bank. Its CMOS transmission-gate design supports true bidirectional analog signal flow with matched on-resistance (≤16Ω) and flatness (≤10Ω) over ±3V input range.

It operates across three supply configurations: dual ±2.7V to ±8V, single +2.7V to +16V, or +3V/+5V/+12V single-ended - with logic thresholds (0.8V/2.4V) ensuring TTL/CMOS compatibility. RESET asynchronously clears all switches and resets the shift register to zero.

Key Specifications

Pinout & Package

MAX350CPN+ is housed in an 18-pin plastic DIP (dual in-line package) with 0.3-inch body width and through-hole mounting. Pin 1 is top-left corner (notch side), with pins numbered counter-clockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADG732BRUZ and TMUX1308PWR, the MAX350CPN+ uniquely delivers dual independent 4:1 switching, ±8V analog operation, and hardware RESET - making it irreplaceable in ruggedized industrial and aerospace signal-routing applications requiring guaranteed fail-safe initialization and bipolar signal integrity.

Availability

MAX350CPN+ is available at Aetrix Electronics and suitable for industrial data-acquisition systems, avionics signal conditioning, and automated test equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing from authorized channels.

Supply support for MAX350CPN+ 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 MAX350CPN+ belongs to Maxim's serially controlled analog switch/multiplexer product line, engineered specifically for high-reliability, low-leakage, rail-to-rail signal routing in environments with wide supply ranges and stringent ESD requirements (>2kV).

FAQ

What is the maximum supply voltage range supported by the MAX350CPN+?

The MAX350CPN+ supports dual supplies from ±2.7V to ±8V, or a single supply from +2.7V to +16V. At ±5V, on-resistance is guaranteed ≤100Ω; operation beyond ±8V or +16V risks permanent damage per Absolute Maximum Ratings. The device maintains rail-to-rail signal handling across this full range, enabling direct interface with both legacy ±5V op-amps and modern 3.3V/12V systems. Always observe V+ and V− limits relative to GND.

How does the MAX350CPN+ handle bidirectional analog signal routing?

The MAX350CPN+ uses symmetrical CMOS transmission gates, allowing signals to pass equally well from NOx to COM or COM to NOx. Its on-resistance (≤100Ω) and leakage (≤0.1nA at +25°C) are specified identically in both directions. This bidirectionality is intrinsic to the switch architecture - no configuration or external circuitry is required. It enables flexible use cases such as feeding a DAC output to multiple destinations or sampling from multiple sensors into one ADC.

Can multiple MAX350CPN+ devices be connected in series using the DOUT pin?

Yes - the MAX350CPN+ features a dedicated DOUT pin that outputs the Q7 stage of its internal 8-bit shift register, enabling seamless daisy-chaining. Connect DOUT of one device to DIN of the next, tie all CS and SCLK lines together, then shift 8×N bits to program N devices. On the final CS rising edge, all devices update simultaneously. Note: DOUT logic high equals V+, so level-shifting may be needed if cascading into 3.3V logic domains.

What is the function of the RESET pin on the MAX350CPN+?

The RESET pin on the MAX350CPN+ provides asynchronous, hardware-level initialization: pulling it low forces all eight switches OFF and resets the internal shift register to 00000000, regardless of CS or SCLK state. This guarantees a known, safe default condition at power-up or after fault detection. Unlike software reset via serial command, RESET requires no clock cycles or valid data - making it essential for safety-critical applications like avionics and industrial safety controllers.

Is the MAX350CPN+ compatible with standard SPI interfaces?

Yes - the MAX350CPN+ implements a 3-wire SPI-compatible interface (DIN, SCLK, CS) with CPOL = 0 and CPHA = 0 timing. Data is sampled on the rising edge of SCLK while CS is low; DOUT returns shifted-out data on the falling edge. It supports up to 2.1MHz SCLK and tolerates standard 3.3V/5V logic levels. No additional protocol translation is required when connecting to microcontrollers with native SPI peripherals - simply configure as a standard slave device with active-low chip select.