Analog Devices Inc./Maxim Integrated MAX144ACPA

Overview

MAX144ACPA from Maxim Integrated is a low-power, 12-bit successive-approximation analog-to-digital converter (SAR ADC) with two single-ended input channels, 108ksps sampling rate, ±0.5 LSB INL, and operation from +2.7V to +5.25V supply - used in portable data loggers for precision sensor digitization under battery-constrained conditions.

For engineers reviewing the MAX144ACPA datasheet, MAX144ACPA pinout, MAX144ACPA application, or MAX144ACPA equivalent, this page delivers verified electrical parameters, DIP-8 package layout, SPI/QSPI/MICROWIRE interface timing constraints, and real-world trade-offs versus 10-bit and temperature-extended alternatives.

Technical Context

The MAX144ACPA implements a SAR architecture with integrated track-and-hold, internal laser-trimmed oscillator (2MHz ±20%), and automatic power-down mode that reduces current to 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 per sample.

Analog input structure uses a 16pF hold capacitor and 9kΩ input resistance; acquisition time t_ACQ = 7µs (typical) depends on source impedance. Input protection diodes clamp CH0/CH1 to GND −300mV and VDD +300mV, but accurate conversion requires signals within GND −50mV to VDD +50mV.

Key Specifications

Pinout & Package

MAX144ACPA is housed in an 8-pin plastic DIP (dual in-line package) with 0.3-inch body width and through-hole mounting. Pin pitch is 0.1 inch (2.54mm); leads are tin-lead plated and RoHS-compliant per Maxim's packaging specification P8-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX144BCPA, the MAX144ACPA delivers tighter linearity for calibration-sensitive instrumentation; compared with MAX157CPA, it provides 4× finer quantization steps at only +0.3mA supply current penalty - justifying its use in high-fidelity sensor nodes.

Availability

MAX144ACPA is available at Aetrix Electronics and suitable for portable data logging, battery-powered systems, and process-control monitoring requiring stable component supply across extended production lifecycles.

Supply support for MAX144ACPA 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 was engineered specifically for low-power, high-accuracy data acquisition in space-constrained and energy-limited systems - emphasizing single-supply operation, fast wake-up, and minimal external components.

FAQ

What is the maximum sampling rate of the MAX144ACPA, and how is it achieved?

The MAX144ACPA achieves a maximum sampling rate of 108ksps using external clock mode with SCLK set to 2.17MHz. In this mode, conversion begins on the falling edge of the second SCLK pulse, and the 7.4µs conversion time is strictly enforced. The device must complete conversion within 140µs to avoid T/H capacitor droop-induced errors. At 108ksps, supply current is 0.9mA with +3V supply.

Does the MAX144ACPA require an external reference, and what are its key specifications?

Yes, the MAX144ACPA requires an external reference applied to the REF pin. It must deliver ≥250µA DC load current during conversion and exhibit ≤10Ω output impedance. A 0.1µF ceramic capacitor is mandatory at REF for stability. The reference voltage sets the full-scale range (0V to VREF), and the device accepts inputs from 0V to VDD+50mV, though optimal performance occurs at 2.5V.

How does the MAX144ACPA enter and exit shutdown mode, and what is the wake-up time?

The MAX144ACPA enters shutdown when CS/SHDN is driven high, reducing supply current to ≤0.2µA. Wake-up occurs on the falling edge of CS/SHDN, with a guaranteed 2.5µs delay before DOUT becomes valid and conversion begins. If the external reference is not stable to within 1 LSB, additional stabilization time beyond 2.5µs is required before reliable conversion.

What serial interface standards does the MAX144ACPA support, and what configuration is required?

The MAX144ACPA supports SPI, QSPI, and MICROWIRE protocols. It requires CPOL = 0 and CPHA = 0 configuration. Data is MSB-first, with DOUT transitioning on the falling edge of SCLK and sampled on the rising edge. The 16-bit output frame includes three leading ones, a channel ID bit, and 12 data bits - compatible with standard microcontroller SPI peripherals without modification.

Can the MAX144ACPA operate with a 5V supply, and what is its power dissipation at that voltage?

Yes, the MAX144ACPA operates across +2.7V to +5.25V. At +5V and 108ksps, typical supply current is 2.0mA, resulting in 10mW power dissipation. The plastic DIP package has a thermal derating factor of 9.09mW/°C above +70°C, with a maximum continuous power dissipation of 727mW at TA = +70°C - well above operational needs.