Analog Devices Inc./Maxim Integrated MAX144ACUA

Overview

MAX144ACUA from Maxim Integrated is a 12-bit, 2-channel, single-ended successive-approximation analog-to-digital converter (ADC) operating from +2.7V to +5.25V supply, delivering 108ksps sampling rate, ±0.5 LSB INL, and 7.4µs conversion time in an 8-pin µMAX package. It integrates on-chip track/hold, internal clock, SPI/QSPI/MICROWIRE-compatible 3-wire serial interface, and automatic power-down mode - enabling precision data acquisition in space-constrained, battery-powered instrumentation.

For engineers reviewing the MAX144ACUA datasheet, MAX144ACUA pinout, MAX144ACUA application, or MAX144ACUA equivalent, this page delivers verified electrical specs, validated pin functions, real-world use cases in isolated sensing and portable logging, and two confirmed alternative parts with documented functional and parametric differences - all grounded in Maxim's official datasheet Rev 2 (10/05).

Technical Context

The MAX144ACUA implements a SAR architecture with integrated track-and-hold, where acquisition occurs on the falling edge of CS/SHDN and conversion completes in exactly 16 clock cycles. Its analog input structure supports two single-ended channels (CH0, CH1), both referenced to GND, with channel switching controlled by CS/SHDN toggling.

It operates in dual clock modes: internal oscillator (2MHz ±20%, usable up to 5MHz SCLK for readout) or external clock (100kHz–2.17MHz), with timing-critical sampling on the second SCLK falling edge in external mode. The REF input requires ≥18kΩ DC impedance and ≤10Ω source impedance to maintain 12-bit accuracy.

Key Specifications

Pinout & Package

MAX144ACUA is housed in an 8-pin µMAX package (package code U8-1), measuring 3mm × 3mm × 0.8mm with exposed pad for thermal enhancement. Pin pitch is 0.65mm; recommended PCB footprint follows Maxim's U8-1 land pattern.

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 MAX144ACUA uniquely combines dual single-ended channels, on-chip T/H, automatic shutdown, and wide supply range in a thermally enhanced µMAX package - making it optimal for space-constrained, multi-sensor, battery-operated systems demanding guaranteed 12-bit linearity across 0°C to +70°C.

Availability

MAX144ACUA is available at Aetrix Electronics and suitable for battery-powered data loggers, isolated industrial sensors, portable medical instruments, and process-control monitoring systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MAX144ACUA 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, automotive, and communications markets.

The MAX144 series belongs to Maxim's precision data-acquisition product line, designed specifically for low-power, space-constrained applications requiring reliable 12-bit performance with minimal external components and flexible serial interfacing.

FAQ

What is the maximum sampling rate of the MAX144ACUA, and how is it achieved?

The MAX144ACUA achieves a maximum sampling rate of 108ksps using its external clock mode with SCLK set to 2.17MHz. In this mode, conversion begins on the falling edge of the second SCLK pulse and completes in 16 clock cycles (7.4µs). This rate is guaranteed across the full 0°C to +70°C operating range and requires a stable external reference with ≤10Ω output impedance to maintain 12-bit accuracy. The MAX144ACUA cannot exceed 108ksps - higher rates degrade INL and SNR.

Does the MAX144ACUA require an external reference, and what are the key requirements?

Yes, the MAX144ACUA requires an external reference applied to the REF pin. The reference must deliver ≥250µA DC load current with ≤10Ω output impedance and be bypassed with a 0.1µF ceramic capacitor placed directly at the REF pin. The input resistance at REF is ≥18kΩ, and the valid voltage range is 0V to VDD + 50mV. Using a 2.5V reference (e.g., MAX6126) ensures full 12-bit dynamic range; lower references reduce effective resolution due to increased noise impact.

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

The MAX144ACUA alternates between CH0 and CH1 automatically: after power-up, it samples CH0 first, then CH1, and continues alternating. Channel switching is triggered by toggling the CS/SHDN pin - a falling edge initiates conversion on the next channel. To sample the same channel repeatedly, toggle CS/SHDN twice between conversions. The channel ID bit (CHID) is always included in the 16-bit output stream, appearing as bit 12 (MSB-3), allowing unambiguous identification of the source channel in software.

What are the power consumption characteristics of the MAX144ACUA at different throughput rates?

At 108ksps and +3V supply, the MAX144ACUA draws 0.9mA (2.7mW). At 10ksps, current drops to 100µA; at 1ksps, it falls to 10µA. In shutdown mode (CS/SHDN = VDD), supply current is 0.2µA - a 4500× reduction. These values are measured per Maxim's datasheet Rev 2 and include all internal circuitry; no external components contribute to these figures. Wake-up time from shutdown is 2.5µs, enabling rapid response to event-driven sampling triggers.

Is the MAX144ACUA compatible with standard microcontroller SPI peripherals, and what configuration is required?

Yes, the MAX144ACUA is fully compatible with standard SPI peripherals when configured with CPOL = 0 and CPHA = 0. Conversion starts on the falling edge of CS/SHDN, and DOUT transitions on the falling edge of SCLK while data is latched on the rising edge. The 16-bit output frame (three leading 1s + CHID + 12 data bits) requires two 8-bit reads. No special timing constraints beyond tSCLKS (60ns setup) and tCS (60ns hold) apply - matching common MCU SPI timing margins.