Analog Devices Inc./Maxim Integrated MAX144AEUA

Overview

MAX144AEUA 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, ±0.5 LSB INL, and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface - used in portable data loggers for battery-constrained voltage monitoring.

For engineers reviewing the MAX144AEUA datasheet, MAX144AEUA pinout, MAX144AEUA application, or MAX144AEUA 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-limited embedded sensing systems.

Technical Context

The MAX144AEUA implements a SAR architecture with integrated track-and-hold, supporting internal clock mode (2MHz oscillator, 0–5MHz SCLK) or external clock mode (100kHz–2.17MHz), where conversion begins on the falling edge of the second SCLK pulse. It features automatic power-down (<0.2µA shutdown current) and wake-up in 2.5µs.

Analog input structure includes 9kΩ input resistance and 16pF input capacitance, requiring t_ACQ = 7.4µs minimum acquisition time; full-power bandwidth is 1MHz and small-signal bandwidth is 2.25MHz. Input protection diodes clamp CH0/CH1 to GND −300mV and VDD +300mV.

Key Specifications

Pinout & Package

MAX144AEUA is housed in an 8-pin µMAX package (U8-1), measuring 3mm × 3mm × 0.8mm with exposed pad for thermal enhancement and fine-pitch gull-wing leads (0.65mm pitch). This RoHS-compliant surface-mount package enables high-density PCB layouts in handheld instrumentation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX11131AUT+, the MAX144AEUA uniquely combines guaranteed ±0.5 LSB INL over -40°C to +85°C, true 3-wire SPI/QSPI/MICROWIRE compatibility, and autonomous power-down - making it optimal for ruggedized, battery-operated, dual-channel sensing where layout area and firmware overhead are constrained.

Availability

MAX144AEUA is available at Aetrix Electronics and suitable for battery-powered data loggers, portable medical sensors, industrial process monitors, and system supervision circuits requiring stable component supply across extended temperature ranges.

Supply support for MAX144AEUA 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 medical applications.

The MAX144AEUA belongs to Maxim's low-power serial ADC product line, engineered specifically for space- and energy-constrained embedded systems requiring high DC accuracy and robust serial interfacing without external support components.

FAQ

What is the operating temperature range of the MAX144AEUA?

The MAX144AEUA is rated for industrial operation from -40°C to +85°C. This extended range is confirmed in the Ordering Information table and Absolute Maximum Ratings section of the official datasheet. Unlike the 'C' grade (0°C to +70°C), the 'E' suffix denotes full industrial qualification, with all DC and dynamic specifications guaranteed across this span - including ±0.5 LSB INL and 108ksps sampling rate.

Does the MAX144AEUA require an external reference voltage?

Yes, the MAX144AEUA requires an external reference voltage applied to the REF pin. The device does not include an internal reference. The reference must be stable, capable of delivering ≥250µA DC load current, and have output impedance ≤10Ω to maintain ±0.5 LSB INL. A 0.1µF bypass capacitor is mandatory at the REF pin for noise suppression, as specified in the Electrical Characteristics and Applications Information sections.

How does the MAX144AEUA handle channel selection between CH0 and CH1?

The MAX144AEUA alternates automatically between CH0 and CH1 on successive conversions after power-on reset: CH0 is sampled first, then CH1, then CH0 again. Channel switching is controlled by toggling the CS/SHDN pin - a falling edge initiates conversion of the next channel in sequence. To convert the same channel repeatedly, toggle CS/SHDN twice between conversions. The channel ID bit (CHID) is included in the 16-bit serial output stream.

What is the minimum acquisition time (t_ACQ) for the MAX144AEUA, and how is it affected by source impedance?

The MAX144AEUA specifies a typical acquisition time t_ACQ of 7.4µs. This value assumes ideal conditions (low source impedance). For higher source impedances, t_ACQ increases per the formula t_ACQ = 9(R_S + 9kΩ) × 16pF. Source impedances below 1kΩ have negligible impact; above that, a 0.01µF capacitor at each input is recommended to limit bandwidth and ensure stable acquisition without extending conversion dead time.

Is the MAX144AEUA pin-compatible with the 10-bit MAX157 or MAX159?

Yes, the MAX144AEUA is pin-compatible with the MAX157 and MAX159 - both are 8-pin µMAX devices sharing identical pinout, supply, reference, and interface connections. However, the MAX144AEUA provides 12-bit resolution and tighter DC accuracy (±0.5 LSB INL vs ±1 LSB for MAX157), while maintaining the same 3-wire serial protocol and power-down behavior. This allows direct upgrade in existing designs without PCB revision.