Analog Devices Inc./Maxim Integrated MAX1239LEEE+T

Overview

The MAX1239LEEE+T from Maxim Integrated is a 12-bit, 12-channel, low-power analog-to-digital converter (ADC) with integrated track/hold, 2.048V internal reference, I²C-compatible 2-wire serial interface, and operation from a single 2.7V–3.6V supply. It delivers 94.4ksps throughput, ±1 LSB INL, and consumes only 670µA at max rate-enabling high-precision sensing in battery-powered medical instruments and portable test equipment.

For engineers reviewing the MAX1239LEEE+T datasheet, MAX1239LEEE+T pinout, MAX1239LEEE+T application, or MAX1239LEEE+T equivalent, this page provides verified technical context, real-world design implications of its 12-channel differential input architecture, I²C high-speed mode timing, AutoShutdown™ power management, and validated alternative options for multichannel data acquisition systems.

Technical Context

The MAX1239LEEE+T implements successive-approximation ADC architecture with fully differential track/hold circuitry and software-configurable unipolar/bipolar, single-ended/differential input modes. Its 12-channel analog multiplexer supports channel-scan mode with internal FIFO, enabling autonomous sequential conversion across AIN0–AIN11.

It operates exclusively in I²C 2-wire mode-supporting Fast Mode (400kHz) and High-Speed Mode (1.7MHz)-with factory-programmed slave address 0110101. Internal clock generation eliminates external timing components, while AutoShutdown™ reduces current to <1µA between conversions at low throughput.

Key Specifications

Pinout & Package

The MAX1239LEEE+T is housed in a 16-pin QSOP package (5.3mm × 10.2mm, 0.635mm pitch), optimized for compact PCB layouts in handheld instrumentation and space-constrained industrial modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel, low-power, I²C ADC applications.

Compared with ADS7953IRHBT and MAX11206ETL+, the MAX1239LEEE+T uniquely balances 12-channel count, I²C simplicity, integrated 2.048V reference, and 94.4ksps throughput at sub-1mA active current-making it optimal for portable, battery-sensitive systems requiring moderate speed and precision without SPI infrastructure or external references.

Availability

The MAX1239LEEE+T is available at Aetrix Electronics and suitable for portable medical monitoring, battery-powered test equipment, and solar-powered remote sensing requiring stable component supply and long-term production continuity.

Supply support for MAX1239LEEE+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) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, medical, and communications markets.

The MAX1236–MAX1239 family was designed specifically for ultra-low-power, multichannel data acquisition in space- and energy-constrained portable systems-emphasizing integration (reference, T/H, clock, I²C), wide supply range, and guaranteed performance across –40°C to +85°C.

FAQ

What is the factory-programmed I²C slave address for MAX1239LEEE+T?

The MAX1239LEEE+T has a fixed 7-bit I²C slave address of 0110101 (0x35 in hexadecimal), with the R/W bit appended during communication. This address is laser-trimmed at wafer test and cannot be modified. The device responds only to this address in both Fast Mode and High-Speed Mode, and requires a repeated START condition after HS-mode entry to initiate valid data transfer.

Does MAX1239LEEE+T support true differential input across all 12 channels?

No. The MAX1239LEEE+T supports fully differential input across six independent pairs (e.g., AIN0–AIN1, AIN2–AIN3, etc.), not across all 12 channels simultaneously. In differential mode, the analog multiplexer selects one "+" and one "–" input from the 12 terminals per conversion cycle, limiting concurrent differential measurements to six channels. Single-ended mode uses all 12 inputs independently against GND.

Can MAX1239LEEE+T operate with an external reference voltage lower than 2.048V?

Yes. The MAX1239LEEE+T accepts external reference voltages from 1.0V to VDD (3.6V max), as specified in the Electrical Characteristics table. When using an external reference below 2.048V, full-scale resolution degrades proportionally (e.g., 1.0V ref yields ~244µV/LSB), but INL and DNL remain ±1 LSB. The internal 2.048V reference is disabled automatically when REF is externally driven.

What is the maximum source impedance supported for accurate sampling on MAX1239LEEE+T?

The MAX1239LEEE+T maintains ±1 LSB accuracy with analog source impedances up to 1.5kΩ. For sources exceeding 1.5kΩ, sampling error increases due to RC time constant limitations in the track/hold acquisition phase. To preserve accuracy, add a 100pF capacitor from each analog input to GND-or use an op-amp buffer-especially when driving from high-Z sensors like thermistors or pH electrodes.

How does AutoShutdown™ affect conversion timing and data integrity in MAX1239LEEE+T?

AutoShutdown™ powers down internal circuitry-including reference, oscillator, and T/H-between conversions, reducing current to <1µA. Upon next I²C read command, the device wakes, reinitializes internal bias points, and performs acquisition/conversion with no loss of data integrity. Wake-up latency adds ≤2µs to total conversion time but does not impact sampled value accuracy or linearity.