Analog Devices Inc./Maxim Integrated MAX11321ATJ+

Overview

MAX11321ATJ+ from Maxim Integrated is a 10-bit, 4-channel SAR analog-to-digital converter with external reference support, 1Msps conversion rate, ±0.4 LSB INL, 61.5dB SINAD at 100kHz, and operates from 2.35V–3.6V supply. It enables post-mux external signal conditioning via accessible AOP/AON (mux outputs) and AIP/AIN (ADC inputs), and targets high-precision, low-power portable data acquisition.

For engineers reviewing the MAX11321ATJ+ datasheet, MAX11321ATJ+ pinout, MAX11321ATJ+ application, or MAX11321ATJ+ equivalent, this device offers verified 10-bit accuracy, SampleSet™-enabled channel sequencing, internal FIFO for burst sampling, bipolar/unipolar input configuration, and TQFN-32 package compatibility with industrial temperature range (–40°C to +125°C).

Technical Context

The MAX11321ATJ+ implements a successive approximation register (SAR) architecture with integrated analog multiplexer and configurable input topology-supporting single-ended, pseudo-differential, and fully differential modes per channel. Its SampleSet™ technology allows user-defined 256-entry channel sequences in external clock mode, reducing microcontroller overhead.

In internal clock mode, it features a 16-entry FIFO and on-chip averaging to improve SNR for noisy signals. External access to mux output (AOP/AON) and ADC input (AIP/AIN) enables discrete signal conditioning-e.g., filtering or gain staging-between multiplexing and digitization, even for differential paths.

Key Specifications

Pinout & Package

MAX11321ATJ+ is housed in a 32-pin, 5mm × 5mm, 0.5mm pitch TQFN package with exposed pad (EP) requiring direct connection to GND plane for thermal and noise performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit SAR ADC applications.

Compared with MAX11321ATJ+, ADS7953IRHBT provides more channels and resolution but forfeits post-mux signal conditioning access, while AD7476ARTZ-REEL7 offers lower power and higher speed for single-ended use-but lacks integrated multiplexing, FIFO, and programmable sequencing entirely.

Availability

MAX11321ATJ+ is available at Aetrix Electronics and suitable for industrial sensor hubs, portable medical monitors, automotive cabin control units, smart energy meter front-ends, and battery-powered instrumentation requiring stable component supply and long-term manufacturability.

Supply support for MAX11321ATJ+ 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 automotive applications.

The MAX11321–MAX11328 family was engineered to solve multichannel data acquisition challenges in space- and power-constrained systems-emphasizing post-mux flexibility, low-noise performance, and intelligent sequencing to reduce host processor burden.

FAQ

What is the maximum sampling rate supported by MAX11321ATJ+?

The MAX11321ATJ+ supports a maximum conversion rate of 1Msps in both internal and external clock modes. At this rate, conversion time is 1000ns in external clock mode (16MHz SCLK) and 5.9µs in internal clock mode. Full-linearity bandwidth remains 500kHz, enabling accurate undersampling of higher-frequency signals when paired with proper anti-alias filtering.

Does MAX11321ATJ+ support differential input configurations?

Yes, MAX11321ATJ+ supports fully differential, pseudo-differential, and single-ended input configurations. In fully differential mode, AIP and AIN serve as the positive and negative ADC inputs, with operational input voltage difference ranging from –VREF+/2 to +VREF+/2 or –VREF+ to +VREF+, depending on RANGE bit setting. This enables direct connection to differential sensors like strain gauges or isolated amplifiers.

How does the SampleSet™ feature work in MAX11321ATJ+?

SampleSet™ is a user-programmable channel sequencer that allows loading of up to 256 unique analog input channel addresses into internal memory. In external clock mode, the MAX11321ATJ+ automatically cycles through this sequence without host intervention-enabling mixed-rate sampling (e.g., slow temperature + fast vibration) and freeing the microcontroller for other tasks while reducing system-level noise and power consumption.

What are the reference voltage requirements for MAX11321ATJ+?

MAX11321ATJ+ requires an external differential reference applied to REF+ and REF– pins. REF+ accepts 1V to VDD + 50mV (max +4V), and REF– accepts –0.3V to +1V. The reference must be stable and low-noise; typical implementation uses a precision 2.5V reference with 0.47µF bypass capacitor to GND at REF+. Reference current is 36.7µA at 1Msps sampling, rising slightly with frequency.

Can MAX11321ATJ+ operate with a 1.8V digital I/O supply?

Yes, MAX11321ATJ+ supports OVDD from 1.5V to 3.6V, making it compatible with 1.8V digital interfaces. Digital pins (CS, SCLK, DIN, DOUT, EOC) are referenced to OVDD, with VIH = 0.75 × OVDD and VIL = 0.25 × OVDD. This allows seamless integration with low-voltage microcontrollers (e.g., ARM Cortex-M0+) without level shifters, while analog core remains powered by separate 2.35V–3.6V VDD rail.