Analog Devices Inc./Maxim Integrated MAX144ACUA+T

Overview

MAX144ACUA+T from Maxim Integrated is a 12-bit, 2-channel, single-ended successive-approximation analog-to-digital converter (ADC) with SPI/QSPI/MICROWIRE-compatible 3-wire serial interface, 108ksps sampling rate, ±0.5 LSB INL, and operation from +2.7V to +5.25V supply - used in portable data loggers for battery-constrained signal digitization.

For engineers reviewing the MAX144ACUA+T datasheet, MAX144ACUA+T pinout, MAX144ACUA+T application, or MAX144ACUA+T equivalent, this page delivers verified electrical specs, µMAX-8 package mapping, real-world acquisition timing (tACQ = 7 µs), shutdown current (0.2 µA), and validated alternative part selection guidance.

Technical Context

The MAX144ACUA+T implements a SAR architecture with integrated track-and-hold, internal clock option (2 MHz ±20%), and automatic power-down triggered by CS/SHDN high. It supports single-ended dual-channel conversion with channel auto-alternation and explicit CHID bit in output stream.

Its analog input structure features 9 kΩ input resistance, 16 pF input capacitance, and ±0.5 LSB channel-to-channel offset matching. The 3-wire serial interface operates in external clock mode (100 kHz–2.17 MHz) or internal clock mode (0–5 MHz data readout), with DOUT active-low enable timing controlled by CS/SHDN.

Key Specifications

Pinout & Package

MAX144ACUA+T is housed in an 8-pin µMAX package (U8-1 code), 3.0 mm × 3.0 mm body, 0.5 mm pitch, exposed pad for thermal enhancement. Pin 1 is VDD; pin 4 is GND; pin 6 is CS/SHDN (dual-function active-high shutdown / active-low chip select); pin 7 is DOUT (3-state, falling-edge synchronized).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX144ACUA+T, ADS7822U offers higher throughput but demands more design effort for reference buffering and power management, while MAX11131AUT+T trades ultra-low shutdown current for integrated reference convenience and higher active power draw.

Availability

MAX144ACUA+T is available at Aetrix Electronics and suitable for portable data logging, battery-powered sensor nodes, and isolated data acquisition requiring stable component supply across industrial and medical OEM programs.

Supply support for MAX144ACUA+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 demanding industrial, medical, and communications applications.

The MAX144 series belongs to Maxim's low-power serial ADC product line, engineered specifically for space- and energy-constrained data acquisition where µMAX packaging, sub-µA shutdown, and SPI compatibility are critical.

FAQ

What is the maximum sampling rate of the MAX144ACUA+T?

The MAX144ACUA+T achieves a maximum sampling rate of 108 ksps under specified conditions (VDD = +3.6 V, fSCLK = 2.17 MHz, 16 clocks/conversion). This rate is sustained with full 12-bit accuracy and ±0.5 LSB INL over the 0°C to +70°C temperature range. At lower throughput rates (e.g., 10 ksps), supply current drops to 100 µA, enabling further power savings in duty-cycled systems.

Does the MAX144ACUA+T require an external reference voltage?

Yes, the MAX144ACUA+T requires an external reference voltage applied to the REF pin. It accepts 0 V to VDD + 50 mV, with optimal performance at 2.5 V. A minimum 18 kΩ DC input resistance and ability to source 250 µA during conversion are required. A 0.1 µF ceramic capacitor must be placed close to the REF pin to ensure stability and low-noise operation - no internal reference is provided.

How does the MAX144ACUA+T handle channel selection between CH0 and CH1?

The MAX144ACUA+T automatically alternates 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 starts CH0 conversion, the next starts CH1. A channel identification (CHID) bit is included in the 16-bit serial output stream (bit 13), allowing firmware to unambiguously identify which channel produced each result.

What is the wake-up time from shutdown mode for the MAX144ACUA+T?

The MAX144ACUA+T wakes up from shutdown mode in 2.5 µs when CS/SHDN transitions from high to low and the external reference is stable within ±1 LSB. If the reference is not stabilized to that tolerance, wake-up time must be extended to allow settling - typically adding 1–2 µs margin. This fast wake-up enables burst-mode sampling with minimal latency penalty.

Is the MAX144ACUA+T pin-compatible with any 10-bit alternatives?

Yes, the MAX144ACUA+T is pin-compatible with the MAX157 and MAX159 - 10-bit versions in identical 8-pin µMAX packages. These share the same pinout, supply range, serial interface timing, and shutdown behavior. However, they offer reduced resolution (10-bit), lower INL (±0.5 LSB), and slightly lower power (0.5 mA at 100 ksps), making them suitable for cost-sensitive applications where 12-bit precision is not required.