Analog Devices Inc./Maxim Integrated MAX1238KEEE+

Overview

MAX1238KEEE+ from Maxim Integrated is a 12-bit, 12-channel analog-to-digital converter with integrated track/hold, 4.096V internal reference, I²C-compatible 2-wire serial interface, and single-supply operation from 4.5V to 5.5V. It delivers 94.4ksps throughput, consumes only 670µA at max rate, and supports software-configurable unipolar/bipolar and single-ended/differential input modes for precision sensor and system monitoring applications.

For engineers reviewing the MAX1238KEEE+ datasheet, MAX1238KEEE+ pinout, MAX1238KEEE+ application, or MAX1238KEEE+ equivalent, this page provides verified technical context, validated pin functions, confirmed operating parameters, and real-world selection guidance - all grounded in Maxim's official MAX1236–MAX1239 datasheet (Rev 7, May 2010).

Technical Context

The MAX1238KEEE+ implements successive-approximation ADC architecture with fully differential track-and-hold circuitry and an internal 2.8MHz oscillator. Its 12-channel analog multiplexer supports channel-scan mode with internal FIFO, enabling automated sequential conversions across AIN0–AIN11.

It operates exclusively in I²C slave mode with factory-programmed 7-bit slave address 0110101 (0x35), supporting both Fast Mode (400kHz) and High-Speed Mode (1.7MHz). Conversion timing is synchronized to either internal clock or external SCL, with aperture delay as low as 30ns in HS-mode.

Key Specifications

Pinout & Package

The MAX1238KEEE+ is housed in a 16-pin QSOP package (5.3mm × 10.2mm, 0.635mm pitch), optimized for space-constrained industrial and portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7953IRHBT and MAX11206ETL+, the MAX1238KEEE+ uniquely balances 12-channel count, I²C simplicity, 5V compatibility, and integrated 4.096V reference - making it optimal for mid-speed, multi-sensor embedded systems requiring minimal external components.

Availability

MAX1238KEEE+ is available at Aetrix Electronics and suitable for industrial sensor hubs, portable medical monitors, and solar charge controllers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX1238KEEE+ 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, medical, and communications applications.

The MAX1236–MAX1239 family was designed for low-power, multichannel data acquisition in space- and energy-constrained systems - emphasizing integration, I²C accessibility, and guaranteed operation across -40°C to +85°C.

FAQ

What is the factory-programmed I²C slave address for MAX1238KEEE+?

The MAX1238KEEE+ has a fixed 7-bit I²C slave address of 0110101 (0x35), as specified in the Ordering Information table of the MAX1236–MAX1239 datasheet. This address is hard-coded during manufacturing and cannot be altered. The R/W bit (LSB) determines read/write direction: 0 for write, 1 for read. No external address pins or configuration registers modify this value.

Does MAX1238KEEE+ support external reference input, and what is the valid voltage range?

Yes, the MAX1238KEEE+ supports external reference input applied to the AIN3/REF or AIN11/REF pins. The valid external reference voltage range is 1V to VDD (4.5V–5.5V), as confirmed in the Electrical Characteristics table. When using an external reference, the internal 4.096V reference is disabled, and full-scale range becomes proportional to the applied VREF - enabling custom scaling for specific sensor outputs.

What is the maximum achievable sampling rate for MAX1238KEEE+, and what conditions are required?

The MAX1238KEEE+ achieves a maximum sampling rate of 94.4ksps when operating in High-Speed I²C Mode (1.7MHz SCL) with external clocking and internal reference enabled. This rate requires the bus master to issue the HS-mode master code (00001XXX) first, then perform a repeated START before sending the slave address. Fast Mode (400kHz) limits throughput to 22.2ksps.

How does AutoShutdown™ reduce power consumption in MAX1238KEEE+?

AutoShutdown™ powers down the MAX1238KEEE+'s analog core, reference, and clock circuitry between conversions, reducing supply current to less than 1µA at low throughput rates. This feature activates automatically after each conversion completes and remains active until the next I²C read command initiates a new acquisition cycle - extending battery life in intermittent-sampling applications without firmware intervention.

Can MAX1238KEEE+ operate in differential input mode with bipolar signal ranges?

Yes, the MAX1238KEEE+ supports fully differential input mode with bipolar operation when configured via the BIP/UNI bit in the setup register. In this mode, the input range is ±VREF/2 (±2.048V with internal 4.096V reference), and output codes are delivered in two's complement format. This configuration is validated for AIN pairs such as AIN0–AIN1, AIN2–AIN3, up to AIN10–AIN11, as defined in Table 4 of the datasheet.