Analog Devices Inc./Maxim Integrated MAX1249AEEE+

Overview

MAX1249AEEE+ from Maxim Integrated is a 10-bit, 4-channel serial analog-to-digital converter (ADC) with integrated track/hold, software-configurable unipolar/bipolar and single-ended/differential inputs, and SPI/QSPI/MICROWIRE-compatible 4-wire serial interface. It operates from a single +2.7V to +5.25V supply, consumes only 54µA at 1ksps (+3V), and supports external reference input (2.500V typical). It is used in portable data loggers and battery-powered medical instruments requiring low quiescent current and compact footprint.

For engineers reviewing the MAX1249AEEE+ datasheet, MAX1249AEEE+ pinout, MAX1249AEEE+ application, or MAX1249AEEE+ equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated QSOP-16 pin functions, confirmed alternative parts with documented functional differences, and supply-chain support for industrial embedded and portable instrumentation designs.

Technical Context

The MAX1249AEEE+ uses successive-approximation architecture with an internal track/hold circuit that acquires input signals in ≤1.5µs and supports both internal clock mode (7.5µs max conversion time) and external clock mode (133ksps at 2MHz SCLK). Its analog front-end accepts four single-ended or two pseudo-differential input pairs (CH0/CH1, CH2/CH3), with COM pin defining zero-code voltage in single-ended mode.

It features a three-level SHDN pin enabling full power-down (1µA), fast power-down (MAX1248 only), or operational modes; requires external 2.500V reference applied to VREF pin; and includes REFADJ buffer with ±1.5% adjustment range and 2.00× gain. The serial interface outputs MSB-first data on DOUT at SCLK falling edge and provides SSTRB strobe synchronized to conversion start/end.

Key Specifications

Pinout & Package

MAX1249AEEE+ is housed in a 16-pin QSOP package (5.3mm × 10.2mm), occupying the same PCB area as an 8-pin SOIC - enabling space-constrained upgrades without layout revision.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1249AEEE+, ADS7822U trades resolution and configurability for ultra-small size and lower cost, while MAX11100ETE+ delivers higher precision and speed in a smaller thermal package but forfeits external reference control and direct QSOP-16 compatibility.

Availability

MAX1249AEEE+ is available at Aetrix Electronics and suitable for portable data logging, battery-powered medical instruments, and system supervision applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MAX1249AEEE+ 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 demanding industrial, medical, and portable applications.

The MAX1248/MAX1249 product line targets low-power, multi-channel data acquisition in space- and energy-constrained systems - emphasizing software-configurable inputs, minimal external components, and robust serial interfacing.

FAQ

What is the reference voltage requirement for MAX1249AEEE+?

The MAX1249AEEE+ requires an external 2.500V reference applied to the VREF pin, with tolerance of ±0.030V (±1.2%) and temperature coefficient of ±30ppm/°C. Unlike the MAX1248, it does not include an internal reference; the REFADJ pin enables ±1.5% fine-tuning of the external reference via a resistor divider. This configuration ensures high-accuracy ratiometric measurements in precision sensor interfaces.

Does MAX1249AEEE+ support differential input mode?

Yes, MAX1249AEEE+ supports pseudo-differential input mode using two channel pairs: CH0/CH1 and CH2/CH3. In this mode, the device samples the voltage difference |CH0 − CH1| or |CH2 − CH3|, with COM serving as the common reference. The input must remain stable within ±0.5LSB on the "−" side during conversion, typically achieved with a 0.1µF capacitor to AGND. Differential mode is selected via the SGL/DIF bit in the control byte.

What is the minimum acquisition time for MAX1249AEEE+?

The guaranteed minimum acquisition time (tACQ) for MAX1249AEEE+ is 1.5µs, defined as the maximum time needed for the internal track/hold to settle to 10-bit accuracy. This value holds regardless of source impedance when the input is properly bypassed; for higher-impedance sources (>3kΩ), tACQ increases per tACQ = 7.6 × (RS + 9kΩ) × 16pF. Accurate conversions require respecting this timing in both internal and external clock modes.

How does the SHDN pin function on MAX1249AEEE+?

The SHDN pin on MAX1249AEEE+ is a three-level control: pulled low → full power-down (1µA supply current); left floating → reference-buffer amplifier enters external compensation mode (requires 4.7µF cap at VREF); pulled high → internal compensation mode (requires 0.01µF cap at REFADJ). Unlike the MAX1248, MAX1249AEEE+ does not support fast power-down - only full power-down and active modes are available.

Can MAX1249AEEE+ interface directly with a TMS320 DSP?

Yes, MAX1249AEEE+ supports direct connection to TMS320-family DSPs via its dedicated SSTRB (serial strobe) output. In internal clock mode, SSTRB goes low at conversion start and high upon completion, providing hardware synchronization for DMA-triggered reads. The 4-wire SPI-compatible interface (SCLK, DIN, DOUT, CS) matches standard DSP serial ports without external logic, and the 2.0MHz max SCLK rate aligns with common DSP peripheral clock domains.