Analog Devices Inc./Maxim Integrated MAX1246AEEE+

Overview

MAX1246AEEE+ from Maxim Integrated is a 12-bit, 4-channel serial analog-to-digital converter (ADC) with integrated track/hold, software-configurable unipolar/bipolar and single-ended/differential inputs, internal 2.5V reference, and SPI/QSPI/MICROWIRE-compatible 4-wire interface. It operates from a single +2.7V to +3.6V supply, achieves 133ksps conversion rate, and draws only 1.2mA at full speed-enabling high-precision data acquisition in battery-powered medical instruments and portable data loggers.

For engineers reviewing the MAX1246AEEE+ datasheet, MAX1246AEEE+ pinout, MAX1246AEEE+ application, or MAX1246AEEE+ equivalent, key selection considerations include its QSOP-16 package, internal reference accuracy (±0.5 LSB INL), shutdown current (<1µA), 1.5µs acquisition time, and compatibility with TMS320-family DSPs via SSTRB strobe output.

Technical Context

The MAX1246AEEE+ employs a successive-approximation register (SAR) architecture with a capacitive DAC and integrated track/hold circuitry. Its analog front-end supports pseudo-differential sampling with channel-to-channel offset matching of ±0.25 LSB and small-signal bandwidth of 2.25MHz.

It features dual clock modes: internal clock (7.5MHz typical) for autonomous conversion timing, or external serial clock (up to 2MHz) for synchronized data transfer. The 8-bit control byte configures channel selection, input polarity, single-ended/differential mode, and power-down state-enabling flexible system-level integration without external logic.

Key Specifications

Pinout & Package

MAX1246AEEE+ is housed in a 16-pin QSOP package (5.3mm × 10.2mm), occupying the same PCB footprint as an 8-pin SOIC-enabling compact, space-constrained designs without layout redesign.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX11100ETE+, the MAX1246AEEE+ uniquely balances integrated reference, 4-channel flexibility, TMS320-compatible strobe, and ultra-low shutdown current-making it optimal for portable, multi-sensor systems requiring minimal external components and deterministic timing.

Availability

MAX1246AEEE+ is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered test equipment requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX1246AEEE+ 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 fabless semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The MAX1246AEEE+ belongs to Maxim's precision data-acquisition product line, designed specifically for low-power, multi-channel, serial-interface ADC applications in space- and energy-constrained embedded systems.

FAQ

What is the operating temperature range for the MAX1246AEEE+?

The MAX1246AEEE+ is specified for operation from 0°C to +70°C. This commercial-grade temperature range is validated per the device's AC and DC electrical characteristics in the official Maxim datasheet, and applies to all performance parameters including INL, gain error, and conversion rate. The MAX1246AEEE+ part number explicitly denotes the "A" grade (0°C to +70°C), distinguishing it from "E" (–40°C to +85°C) and "M" (–55°C to +125°C) variants. Designers should verify thermal margins in their end equipment to ensure ambient conditions remain within this range during MAX1246AEEE+ operation.

Does the MAX1246AEEE+ require an external reference voltage?

No, the MAX1246AEEE+ does not require an external reference voltage because it integrates a precision 2.500V internal reference with ±0.8mV initial accuracy at +25°C and ±30ppm/°C temperature coefficient. This internal reference is enabled by default and buffered at the VREF pin, eliminating the need for external reference ICs or trimming networks. The REFADJ pin allows ±1.5% adjustment for calibration purposes, and the reference can be disabled entirely by tying REFADJ to VDD-though doing so would render the MAX1246AEEE+ nonfunctional unless an external reference is supplied (which is not supported by this variant). The MAX1246AEEE+ is distinct from the MAX1247 family, which requires external reference.

How many analog input channels does the MAX1246AEEE+ support, and how are they configured?

The MAX1246AEEE+ supports four analog input channels (CH0–CH3), configurable via an 8-bit serial control byte. In single-ended mode (SGL/DIF = 1), each channel references COM for unipolar (0V to VREF) or bipolar (±VREF/2) conversion. In differential mode (SGL/DIF = 0), CH0/CH1 and CH2/CH3 form two independent pseudo-differential pairs. Configuration is fully software-controlled-no hardware modifications are needed to switch between modes or channels. The MAX1246AEEE+ does not support true differential sampling (where both inputs are actively sampled); instead, it samples the positive input while holding the negative input stable, requiring careful grounding and bypassing of the COM node to maintain ±0.5 LSB accuracy.

What serial interface protocols is the MAX1246AEEE+ compatible with?

The MAX1246AEEE+ is natively compatible with SPI™, QSPI™, and MICROWIRE™ serial protocols through its 4-wire interface (SCLK, DIN, DOUT, CS) and supports direct connection to TMS320-family DSPs via the SSTRB strobe output. It uses standard MSB-first, clock-idle-low (CPOL = 0), sample-on-rising-edge (CPHA = 0) timing-matching standard SPI master configurations. No external logic or level translation is required for interfacing with microcontrollers such as ARM Cortex-M or Renesas RX series. The control byte format (Table 1 in datasheet) and timing diagrams (Figures 5–9) define exact setup/hold requirements, ensuring reliable communication at clock frequencies from 100kHz to 2MHz.

What is the minimum acquisition time required for accurate conversions with the MAX1246AEEE+?

The guaranteed minimum acquisition time for the MAX1246AEEE+ is 1.5µs, measured from the falling edge of SCLK after the eighth bit of the control byte. This time allows the internal track/hold capacitor to settle to within 1/2 LSB of final value for source impedances ≤1kΩ. For higher source impedances, acquisition time increases per tACQ = 9 × (RS + 9kΩ) × 16pF, and designers must add 0.01µF capacitors at each analog input to limit bandwidth and prevent settling errors. Failure to meet this acquisition window results in increased DNL and degraded effective number of bits (ENOB), particularly noticeable above 10kHz input frequencies. The 1.5µs specification is tested and guaranteed across the full 0°C to +70°C temperature range for the MAX1246AEEE+.