Analog Devices Inc./Maxim Integrated MAX155AEWI+T

Overview

The MAX155AEWI+T from Maxim Integrated is an 8-channel, 8-bit simultaneous-sampling analog-to-digital converter (ADC) with integrated track-and-hold amplifiers, 2.5V internal reference, and 3.6µs per-channel conversion time. It supports unipolar/bipolar and single-ended/differential input configurations, operates from +5V or ±5V supplies, and stores results in an internal 8×8 RAM - enabling phase-coherent data acquisition for vibration analysis and power metering.

For engineers reviewing the MAX155AEWI+T datasheet, MAX155AEWI+T pinout, MAX155AEWI+T application, or MAX155AEWI+T equivalent, this device is selected when precise channel-to-channel timing alignment, on-chip reference stability, and mixed-input-mode flexibility are required in embedded measurement systems without external T/H circuitry.

Technical Context

The MAX155AEWI+T implements a successive-approximation ADC core with eight independent track-and-hold amplifiers that sample all analog inputs simultaneously on the falling edge of WR. Its configuration register-accessed via bidirectional D0–D7 pins-controls channel selection, input polarity (unipolar/bipolar), signal mode (single-ended/differential), power-down, and sequential vs. specific-channel readout.

It supports two interface modes: Input/Output (MODE = open) for full programmability, and Hard-Wired (MODE tied high/low with VSS) for fixed 4- or 8-channel conversions without register writes. The internal 2.5V reference (REFOUT) requires 4.7µF + 0.1µF bypassing; REFOUT may be disabled by connecting to VDD when using an external reference at REFIN.

Key Specifications

Pinout & Package

The MAX155AEWI+T is housed in a 28-pin wide SO (Small Outline) package with 300 mil body width and standard gull-wing leads. Pin 1 is marked with a dot; pin numbering follows counter-clockwise convention from top-left corner when viewed from component side.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel simultaneous-sampling ADC applications.

Compared with AD7864-1ASTZ and ADS8556IPMR, the MAX155AEWI+T uniquely balances 8-channel simultaneous sampling, internal 2.5V reference, parallel 8-bit interface, and ±1 LSB accuracy - making it optimal for cost-sensitive, space-constrained systems needing phase-coherent 8-input capture without external support components.

Availability

The MAX155AEWI+T is available at Aetrix Electronics and suitable for phase-sensitive data acquisition, vibration monitoring, and AC power metering requiring stable component supply across industrial temperature ranges (–40°C to +85°C).

Supply support for MAX155AEWI+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 industrial, medical, and communications applications.

The MAX155AEWI+T belongs to Maxim's high-speed data-acquisition product line, engineered specifically for applications demanding temporal coherence across multiple analog inputs - such as power quality analyzers and structural health monitoring systems.

FAQ

What is the operating temperature range for the MAX155AEWI+T?

The MAX155AEWI+T is rated for operation from –40°C to +85°C (E-grade), making it suitable for industrial environments including outdoor power metering and factory-floor vibration sensors. This extended range is confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables of the official datasheet, with full performance guaranteed across the entire span.

Does the MAX155AEWI+T require external track-and-hold circuitry?

No, the MAX155AEWI+T integrates eight independent track-and-hold amplifiers - one per analog input - eliminating the need for external T/H components. All eight channels sample simultaneously on the falling edge of the WR signal, ensuring inherent phase alignment critical for coherent multi-signal analysis.

Can the MAX155AEWI+T operate with only a +5V supply?

Yes, the MAX155AEWI+T functions with a single +5V supply (VDD = +5V, VSS = 0V) for unipolar input ranges (0 V to +2.5 V). For bipolar operation (±2.5 V), VSS must be connected to –5V - a capability explicitly supported in the Electrical Characteristics and Absolute Maximum Ratings sections.

How does the MAX155AEWI+T handle channel configuration changes during operation?

The MAX155AEWI+T uses a configuration register updated on WR rising edges. Changes to unipolar/bipolar (BIP) or single-ended/differential (DIFF) settings take effect on the *next* conversion - not the current one - to ensure deterministic timing. This behavior is documented in the Multiplexer and A/D Configuration section and verified in timing diagrams Figure 4a–5b.

Is the internal 2.5V reference of the MAX155AEWI+T stable enough for precision measurements?

Yes, the MAX155AEWI+T's internal 2.5V reference exhibits ±100 ppm/°C temperature drift and ±60 mV total variation over –40°C to +85°C, as specified in the Electrical Characteristics table. When properly bypassed with 4.7µF + 0.1µF capacitors to AGND, it meets the accuracy requirements for Class 0.5 power meters and vibration analysis systems.