Analog Devices Inc./Maxim Integrated MAX144BEUA+

Overview

MAX144BEUA+ from Maxim Integrated is a -40°C to +85°C industrial-grade, 12-bit successive-approximation analog-to-digital converter (ADC) with two single-ended input channels, 108ksps sampling rate, ±1 LSB INL, and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface - used in portable data loggers for high-accuracy voltage monitoring under battery-constrained conditions.

For engineers reviewing the MAX144BEUA+ datasheet, MAX144BEUA+ pinout, MAX144BEUA+ application, or MAX144BEUA+ equivalent, this page delivers verified electrical specs, µMAX-8 package terminal mapping, real-world acquisition timing constraints, and validated drop-in alternatives for low-power, space-sensitive embedded ADC selection.

Technical Context

The MAX144BEUA+ implements a SAR architecture with integrated track-and-hold (T/H), internal laser-trimmed oscillator (2MHz ±20%), and automatic power-down mode (0.2µA). It supports both internal clock mode (SCLK high at CS/SHDN fall) and external clock mode (SCLK low at CS/SHDN fall), with conversion time fixed at 7.4µs (16 clocks @ 2.17MHz).

Analog input structure uses 9kΩ input resistance and 16pF input capacitance; acquisition time tACQ = 7µs (typical) is defined by source impedance and RC time constant. Input protection diodes clamp CH0/CH1 to GND −300mV / VDD +300mV, but accurate conversion requires signals within GND −50mV to VDD +50mV.

Key Specifications

Pinout & Package

MAX144BEUA+ is housed in an 8-pin µMAX package (U8-1 code), 3mm × 3mm body, 0.5mm pitch, exposed pad (not electrically connected), RoHS-compliant, thermal resistance θ_JA = 244°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit serial ADC applications.

Compared with MAX144AEUA+, the MAX144BEUA+ trades 0.5 LSB linearity for broader production availability and lower unit cost; versus ADS7822U, it adds internal clock flexibility and faster wake-up but lacks 200ksps throughput - making it optimal for battery-limited, temperature-varying, space-constrained acquisition where 108ksps suffices.

Availability

MAX144BEUA+ is available at Aetrix Electronics and suitable for portable data logging, battery-powered instrumentation, and isolated industrial sensing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX144BEUA+ 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, medical, and communications applications.

The MAX144 series targets low-power, high-accuracy data acquisition in space-constrained environments - delivering 12-bit resolution with µMAX packaging, single-supply operation, and robust serial interface compatibility.

FAQ

What is the operating temperature range of the MAX144BEUA+?

The MAX144BEUA+ is specified for operation from -40°C to +85°C, meeting industrial temperature requirements. This range is confirmed in the Ordering Information table and applies to all DC and AC performance parameters unless otherwise noted in the Electrical Characteristics section. The device maintains ±1 LSB INL and 108ksps sampling rate across this full range.

Does the MAX144BEUA+ require an external reference voltage?

Yes, the MAX144BEUA+ requires an external reference voltage applied to the REF pin. It does not include an internal reference. The reference must be stable, capable of supplying ≥250µA DC load current, and have ≤10Ω output impedance. A 0.1µF bypass capacitor is mandatory at the REF pin for optimal noise performance and accuracy.

How does the MAX144BEUA+ handle channel selection between CH0 and CH1?

The MAX144BEUA+ alternates automatically between CH0 and CH1 after power-on reset: CH0 is sampled first, then CH1, repeating continuously. Channel switching is controlled by toggling the CS/SHDN pin - one toggle initiates CH0 conversion, the next initiates CH1. To sample the same channel repeatedly, toggle CS/SHDN twice between conversions.

What is the minimum acquisition time required before a valid conversion on the MAX144BEUA+?

The MAX144BEUA+ specifies a typical acquisition time (tACQ) of 7µs. This is the minimum time the track-and-hold circuit requires to settle after CS/SHDN falls, before the conversion interval begins. For source impedances ≤1kΩ, no additional delay is needed; higher impedances require longer acquisition intervals calculated as tACQ = 9(RS + 9kΩ) × 16pF.

Can the MAX144BEUA+ operate with a 1.8V supply?

No, the MAX144BEUA+ cannot operate with a 1.8V supply. Its absolute minimum supply voltage is +2.7V, and maximum is +5.25V, as stated in Absolute Maximum Ratings and Electrical Characteristics. Operation below 2.7V risks functional failure, increased INL/DNL error, or inability to power the internal oscillator and T/H circuitry reliably.