Analog Devices Inc./Maxim Integrated MAX1246ACEE+T

Overview

MAX1246ACEE+T from Maxim Integrated is a 12-bit, 4-channel serial analog-to-digital converter (ADC) with integrated track/hold, multiplexer, and internal 2.5V reference. It operates from a single +2.7V to +3.6V supply, supports software-configurable unipolar/bipolar and single-ended/differential inputs, and achieves 133ksps conversion rate using an external 2MHz clock. It targets portable data logging and battery-powered instrumentation where low power and compact size are critical.

For engineers reviewing the MAX1246ACEE+T datasheet, MAX1246ACEE+T pinout, MAX1246ACEE+T application, or MAX1246ACEE+T equivalent, key selection factors include its QSOP-16 package, 1.2mA active current at 133ksps, ±0.5 LSB INL (max), SPI/QSPI/MICROWIRE compatibility, and internal reference-enabling rapid integration into resource-constrained embedded systems without external voltage reference components.

Technical Context

The MAX1246ACEE+T uses successive-approximation register (SAR) architecture with a dedicated track/hold circuit that acquires input signals in ≤1.5µs. Its analog front-end supports four single-ended or two pseudo-differential input channels, with COM pin defining zero-code reference and configurable via control-byte bits SEL2–SEL0, SGL/DIF, and UNI/BIP.

It features dual clock modes: external clock (2MHz max, 12 clocks/conversion) for deterministic timing, or internal clock (0.225MHz typ when SHDN = VDD) for µP flexibility. The 4-wire serial interface (CS, SCLK, DIN, DOUT) is SPI/QSPI/MICROWIRE-compatible with MSB-first, falling-edge data output and automatic power-up on CS assertion.

Key Specifications

Pinout & Package

The MAX1246ACEE+T is housed in a 16-pin QSOP package (5.3mm × 10.2mm), occupying the same PCB footprint as an 8-pin SOIC-enabling space-constrained designs without sacrificing channel count.

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 MAX1246ACEE+T uniquely balances ultra-low shutdown current (1µA), integrated reference, QSOP-16 footprint compatibility with legacy SOIC layouts, and robust 133ksps performance-making it optimal for long-life portable instrumentation where BOM simplicity and layout continuity are prioritized over peak speed.

Availability

MAX1246ACEE+T is available at Aetrix Electronics and suitable for portable data logging, medical instruments, and battery-powered instruments requiring stable component supply, long-term lifecycle support, and guaranteed authentic Maxim Integrated product traceability.

Supply support for MAX1246ACEE+T 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 consumer applications.

The MAX1246/MAX1247 family was designed for low-power, multi-channel data acquisition in space- and energy-constrained systems-emphasizing integrated functionality (mux, T/H, reference) and flexible serial interfacing to reduce system complexity.

FAQ

What is the operating temperature range for the MAX1246ACEE+T?

The MAX1246ACEE+T is specified for operation from 0°C to +70°C. This commercial-grade temperature range aligns with typical indoor portable instrument and data logger use cases. The device's electrical characteristics-including INL, gain error, and reference voltage drift-are guaranteed across this full range per the datasheet's "ELECTRICAL CHARACTERISTICS" tables. No derating or additional thermal management is required within these limits for the MAX1246ACEE+T.

Does the MAX1246ACEE+T require an external reference voltage?

No, the MAX1246ACEE+T does not require an external reference voltage because it integrates a precision 2.500V reference buffer. This internal reference is factory-trimmed to ±0.8% initial accuracy at +25°C and exhibits ±30ppm/°C temperature coefficient over 0°C to +70°C. A 4.7µF capacitor must be placed at the VREF pin for stability, and REFADJ allows ±1.5% adjustment. In contrast, the pin-compatible MAX1247 variant requires an external reference.

How do I configure the MAX1246ACEE+T for differential input mode?

To configure the MAX1246ACEE+T for differential input mode, set bit SGL/DIF = 0 in the 8-bit control byte sent to DIN. Then select channel pairs using SEL2–SEL0: 001 enables CH0–CH1, and 010 enables CH2–CH3. The device performs pseudo-differential sampling-capturing the voltage difference while holding the negative input (IN−) stable to ±0.5 LSB. For best results, connect a 0.1µF capacitor from the selected IN− channel to AGND to minimize droop during conversion.

What is the minimum acquisition time required for accurate conversions with the MAX1246ACEE+T?

The MAX1246ACEE+T specifies a minimum acquisition time (tACQ) of 1.5µs under typical conditions (source impedance ≤1kΩ). This value is derived from the internal track/hold circuit's RC time constant and is guaranteed across the full operating temperature and supply range. If the analog source impedance exceeds 1kΩ, tACQ increases linearly per tACQ = 9 × (RS + 9kΩ) × 16pF, so external input filtering or lower-impedance buffering may be needed to maintain 12-bit accuracy at full 133ksps rate.

Can the MAX1246ACEE+T interface directly with a TMS320 DSP?

Yes, the MAX1246ACEE+T can interface directly with TMS320-family digital signal processors via its SSTRB (serial strobe) output. In internal clock mode, SSTRB asserts low at conversion start and high at completion-providing a ready signal for DMA-triggered data reads. In external clock mode, SSTRB pulses high for one SCLK period before the MSB decision, synchronizing precisely with the DSP's serial port timing. No level-shifting or glue logic is required when both devices share compatible voltage levels (e.g., 3.3V).