Analog Devices Inc./Maxim Integrated MAX11639EEE+

Overview

MAX11639EEE+ from Maxim Integrated is an 8-bit, 8-channel serial analog-to-digital converter (ADC) with integrated track-and-hold, on-chip 16-entry FIFO, internal 2.5V reference, and SPI/QSPI/MICROWIRE-compatible 3-wire interface. It operates from a +2.7V to +3.6V supply, achieves up to 300ksps sampling rate with external clocking, and is specified over –40°C to +85°C for industrial data acquisition and system supervision.

For engineers reviewing the MAX11639EEE+ datasheet, MAX11639EEE+ pinout, MAX11639EEE+ application, or MAX11639EEE+ equivalent, this page delivers verified electrical specs, exact QSOP-16 pin functions, real-world use cases in patient monitoring and instrumentation, and two validated alternative parts with documented functional and supply-voltage differences.

Technical Context

The MAX11639EEE+ uses a successive-approximation register (SAR) architecture with internal track-and-hold supporting unipolar single-ended inputs (0V to VREF). Its conversion timing is configurable via four clock modes - including CNVST-triggered (mode 01) and internally timed scan (mode 00) - enabling flexible integration without serial bus contention.

It integrates a 2.5V internal reference with ±30ppm/°C drift and 200µVRMS noise, supports external reference input (1V to VDD), and features AutoShutdown™ reducing supply current to ≤5µA in shutdown. The 16-deep FIFO buffers results independently of host read timing, critical for burst-mode acquisition in embedded control systems.

Key Specifications

Pinout & Package

MAX11639EEE+ is housed in a 16-pin QSOP package (5.3mm × 10.2mm, 0.65mm pitch), RoHS-compliant and lead-free.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit multichannel ADC applications.

Compared with ADS7822U and MAX11100ETE+, the MAX11639EEE+ uniquely balances low power (≤2mA active), integrated FIFO, and flexible clocking - making it optimal for resource-constrained, multi-sensor embedded systems where deterministic acquisition timing and minimal external components are essential.

Availability

MAX11639EEE+ is available at Aetrix Electronics and suitable for industrial process monitoring, portable medical devices, and battery-powered data loggers requiring stable component supply and long-term manufacturability.

Supply support for MAX11639EEE+ 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 industrial, medical, and communications applications.

The MAX11639EEE+ belongs to Maxim's low-power, multichannel ADC product line engineered for system supervision and embedded data acquisition where small size, integrated references, and FIFO buffering reduce host processor overhead.

FAQ

What is the maximum sampling rate achievable with MAX11639EEE+?

The MAX11639EEE+ achieves up to 300ksps when using an external clock (SCLK ≤10MHz, mode 11). Internally clocked operation supports lower rates (e.g., ~200ksps typical) due to ±10% oscillator tolerance. Real-world throughput depends on FIFO depth, averaging settings, and host read latency - all configurable via the setup and conversion registers.

Does MAX11639EEE+ require an external reference voltage?

No, the MAX11639EEE+ includes a factory-trimmed 2.5V internal reference (2.48V–2.52V) with ±30ppm/°C drift, eliminating the need for external reference components. An external reference (1V to VDD) may be applied via the REF pin if tighter initial accuracy or different voltage scaling is required - but doing so disables the internal reference and increases supply current.

How does the FIFO buffer function in MAX11639EEE+?

The MAX11639EEE+ contains a 16-deep first-in/first-out buffer that stores complete 8-bit conversion results. When enabled, it allows autonomous scanning of multiple channels without host intervention. Once full, new conversions overwrite the oldest data. Host reads the oldest byte via DOUT after each CS falling edge, MSB-first - enabling efficient burst acquisition in interrupt-driven or low-power firmware architectures.

Can MAX11639EEE+ operate from a 3.3V supply?

Yes, the MAX11639EEE+ is explicitly rated for +2.7V to +3.6V operation, making it fully compatible with standard 3.3V logic and power domains. At VDD = 3.3V, its internal 2.5V reference remains stable (±0.02V), supply current is ~1.2mA active (internal ref), and timing parameters (e.g., tACQ = 0.6µs) meet specification - ensuring reliable performance in 3.3V embedded systems.

What is the purpose of the CNVST/AIN7 pin on MAX11639EEE+?

The CNVST/AIN7 pin on MAX11639EEE+ serves a dual role: it functions either as the eighth analog input (AIN7) or as an active-low conversion start trigger, selected via the CKSEL bits in the setup register. In clock mode 01, asserting CNVST initiates a single conversion on the selected channel; in mode 00, it triggers programmed scan sequences - providing hardware-controlled timing independent of the serial interface.