Analog Devices Inc./Maxim Integrated MAX1139LEEE+

Overview

MAX1139LEEE+ from Maxim Integrated is a 10-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 2.7V to 3.6V single supply. It delivers 94.4ksps throughput, ±1 LSB INL/DNL, and supports software-configurable unipolar/bipolar, single-ended/differential inputs - ideal for battery-powered medical instruments and solar-powered remote monitoring systems.

For engineers reviewing the MAX1139LEEE+ datasheet, MAX1139LEEE+ pinout, MAX1139LEEE+ application, or MAX1139LEEE+ equivalent, this page provides verified technical context, validated pin functions, confirmed power-performance tradeoffs at 1ksps–94.4ksps, and real-world use cases in hand-held portable instrumentation where supply current <6µA at low throughput and internal FIFO-assisted channel-scan mode are critical design factors.

Technical Context

The MAX1139LEEE+ implements successive-approximation architecture with fully differential track/hold circuitry and a switched-capacitor DAC. Its 2-wire interface operates in Fast Mode (400kHz) or High-Speed Mode (1.7MHz), requiring explicit HS-mode master code (00001XXX) activation to achieve full 94.4ksps throughput.

It features an internal 2.048V reference (±0.04V over temperature), supports external reference input from 1V to VDD, and enables channel-scan mode via internal FIFO. Analog inputs accept 12 single-ended or 6 fully differential channels, with software-selectable unipolar (0 to VREF) or bipolar (±VREF/2) ranges and two's complement output in bipolar mode.

Key Specifications

Pinout & Package

MAX1139LEEE+ is housed in a 16-pin QSOP package (5.3mm × 10.2mm, 0.635mm pitch), optimized for compact PCB layouts in portable equipment. Pin functions are validated per Maxim's official pin description table and functional diagram.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1138EEE+, MAX1139LEEE+ enables direct 3.3V battery operation and lower system-level power; compared with ADS7822U, it trades 2-bit resolution for integrated reference, I²C simplicity, and autonomous channel scanning - making it superior for ultra-low-power portable instrumentation.

Availability

MAX1139LEEE+ is available at Aetrix Electronics and suitable for medical instrumentation, battery-powered test equipment, and solar-powered remote systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX1139LEEE+ 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 demanding industrial, medical, and communications applications.

The MAX1136–MAX1139 family was designed for ultra-low-power, multichannel data acquisition in space- and energy-constrained portable systems - emphasizing integrated references, intelligent power states, and simplified digital interfacing.

FAQ

What is the maximum sampling rate achievable with MAX1139LEEE+?

The MAX1139LEEE+ achieves a maximum sampling rate of 94.4ksps when operating in High-Speed Mode (HS-mode) with an external 1.7MHz I²C clock. This requires issuing the HS-mode master code (00001XXX) first, followed by a repeated START condition and slave address. In default Fast Mode, the limit is 400kHz clock yielding ~22.2ksps. The MAX1139LEEE+ internal clock runs at 2.8MHz, supporting 94.4ksps only in external-clock configuration.

Does MAX1139LEEE+ require an external reference voltage?

No, the MAX1139LEEE+ does not require an external reference voltage because it integrates a precision 2.048V internal reference (±0.04V over temperature). However, it supports external reference input from 1V to VDD via the AIN11/REF pin when higher accuracy or custom full-scale range is needed. Using the internal reference eliminates BOM cost and board space, while external reference mode allows optimization for specific sensor output ranges.

How many analog input channels does MAX1139LEEE+ support?

The MAX1139LEEE+ supports 12 analog input channels in single-ended mode or 6 fully differential channel pairs. Pins AIN0 through AIN10 are dedicated inputs, while AIN11/REF serves as either the 12th single-ended input or reference terminal depending on configuration bits. Channel selection is controlled via the CS[3:0] field in the configuration byte, and channel-scan mode can automatically cycle through all enabled inputs using the internal FIFO.

What power-saving features does MAX1139LEEE+ include?

The MAX1139LEEE+ incorporates AutoShutdown™, which powers down the ADC core between conversions, reducing supply current to less than 1µA at low throughput rates. At 1ksps, current drops to 6µA; at 10ksps, it is 60µA. This feature is enabled automatically and requires no firmware control. Combined with its 2.7V–3.6V supply range and 670µA max active current, the MAX1139LEEE+ enables multi-year battery life in duty-cycled portable systems.

Is MAX1139LEEE+ compatible with standard I²C protocols?

Yes, the MAX1139LEEE+ implements a fully compliant I²C-compatible 2-wire serial interface supporting both Fast Mode (400kHz) and High-Speed Mode (1.7MHz). It uses standard START/STOP conditions, 7-bit slave address (0110101), acknowledge bits, and bidirectional SDA/SCL signaling. Pull-up resistors ≥750Ω are required on both lines. The device adheres to I²C timing specifications including tSU, DAT, tHD, DAT, and bus capacitance limits (≤400pF per line).