Analog Devices Inc./Maxim Integrated MAX11140ATI+

Overview

MAX11140ATI+ from Maxim Integrated is a 10-bit, 16-channel, 500ksps successive-approximation register (SAR) analog-to-digital converter with external reference support, 1.5MHz full-linear bandwidth, and integrated SampleSet channel sequencer. It operates from 2.35V–3.6V, consumes 4.2mW at 500ksps, and supports single-ended, pseudo-differential, and fully differential input configurations - ideal for multichannel battery-powered data acquisition in industrial sensors and portable medical devices.

For engineers reviewing the MAX11140ATI+ datasheet, MAX11140ATI+ pinout, MAX11140ATI+ application, or MAX11140ATI+ equivalent, key selection criteria include its 10-bit resolution with ±0.4 LSB INL, 8MHz SPI/QSPI/MICROWIRE-compatible 3-wire interface, internal FIFO for burst sampling, AutoShutdown mode (2µA shutdown current), and TQFN-28 package with dedicated OVDD and DGND pins for noise-sensitive mixed-signal layouts.

Technical Context

The MAX11140ATI+ implements a SAR architecture with dual clock modes: internal clock (enabling FIFO buffering and on-chip averaging to improve SNR) and external clock (supporting SampleSet programmable channel sequencing up to 256 steps). Its analog multiplexer delivers true differential track/hold across all 16 inputs, configurable as 16 single-ended, 8 fully differential pairs, or 15 pseudo-differential channels relative to AIN15/REF−.

It features two software-selectable bipolar input ranges (±VREF+/2 or ±VREF+), 7.5MHz −0.1dB full-power bandwidth, and guaranteed 61dB SINAD at 250kHz input frequency. The 3-wire serial interface operates up to 8MHz with precise timing margins (e.g., tDS = 4ns setup, tDH = 1ns hold), and digital I/O is decoupled via separate OVDD (1.5V–3.6V) and DGND rails to isolate analog and digital domains.

Key Specifications

Pinout & Package

MAX11140ATI+ is housed in a 28-pin, 5mm × 5mm TQFN package with exposed pad (EP), rated for −40°C to +125°C operation. Pin functions are validated per Maxim's official pin configuration diagram for the 16-channel variant (MAX11140).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel SAR ADC applications.

Compared with ADS8684IPWR and AD7949BCPZ-RL7, MAX11140ATI+ uniquely balances 10-bit precision, 16-channel count, 500ksps rate, and autonomous SampleSet/FIFO operation - making it optimal for resource-constrained embedded systems requiring flexible, low-overhead multichannel acquisition.

Availability

MAX11140ATI+ is available at Aetrix Electronics and suitable for industrial sensor hubs, portable medical monitors, motor control feedback loops, and smart building occupancy systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX11140ATI+ 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 MAX11135–MAX11143 family was designed to deliver low-power, multichannel SAR ADC performance in space-constrained, battery-operated systems - emphasizing integrated intelligence (SampleSet, FIFO), flexible input routing, and robust noise immunity for harsh environments.

FAQ

What is the maximum sample rate supported by the MAX11140ATI+?

The MAX11140ATI+ supports a maximum conversion rate of 500ksps in both internal and external clock modes. At this rate, conversion time is 2000ns in externally clocked mode (fSCLK = 8MHz) or 5.9µs in internally clocked mode. This enables real-time capture of signals with up to 250kHz bandwidth while maintaining 10-bit resolution and no pipeline delay - critical for closed-loop control and transient event detection.

Does the MAX11140ATI+ require an external reference voltage?

Yes, the MAX11140ATI+ requires an external reference voltage applied to the REF+ pin (1V to VDD), with REF− serving as the reference return or optional 16th analog input. It does not include an internal reference. Using an external reference ensures ratiometric accuracy against sensor excitation sources and supports flexible input ranges (unipolar or bipolar), but mandates proper 0.47µF bypassing at REF+ for stability and noise rejection.

How does the SampleSet feature work on the MAX11140ATI+?

The SampleSet feature on the MAX11140ATI+ is a user-programmable analog input channel sequencer that accepts up to 256 entries defining acquisition order, repetition count, and channel-specific settings. Once loaded, it autonomously cycles through the sequence without host intervention - reducing SPI traffic and MCU overhead. For example, it can scan AIN0 (temp) every 100ms and AIN1–AIN7 (vibration) every 1ms, enabling efficient multirate sensing in battery-powered edge nodes.

What are the power supply requirements for the MAX11140ATI+?

The MAX11140ATI+ requires two independent supplies: VDD (2.35V–3.6V) for analog circuitry and OVDD (1.5V–3.6V) for digital I/O, each with dedicated ground pins (GND and DGND). This separation prevents digital switching noise from degrading analog performance. At 3V VDD and 500ksps, it draws 1.4mA (4.2mW); in full shutdown, current drops to 2µA. A 10µF + 0.1µF bypass network is required on both VDD and OVDD.

Can the MAX11140ATI+ interface directly with a 1.8V microcontroller?

Yes, the MAX11140ATI+ can interface directly with a 1.8V microcontroller because its OVDD pin accepts 1.5V–3.6V, and its digital I/O thresholds scale with OVDD (VIH = 0.75×OVDD, VIL = 0.25×OVDD). With OVDD = 1.8V, VIH = 1.35V and VIL = 0.45V - fully compatible with standard 1.8V logic. No level-shifting circuitry is needed, simplifying design and reducing component count in low-voltage embedded systems.