Analog Devices Inc./Maxim Integrated MAX1246ACPE+

Overview

MAX1246ACPE+ from Maxim Integrated is a 12-bit serial analog-to-digital converter with integrated 4-channel multiplexer, track/hold, 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 with 1.2mA supply current at 3V. It targets portable data logging and battery-powered instrumentation where low power and compact integration are critical.

For engineers reviewing the MAX1246ACPE+ datasheet, MAX1246ACPE+ pinout, MAX1246ACPE+ application, or MAX1246ACPE+ equivalent, key selection considerations include its QSOP-16 package, internal reference accuracy (±0.5 LSB INL), shutdown current (<1µA), SPI/QSPI/MICROWIRE compatibility, and 1.5µs acquisition time - all verified for operation across 0°C to +70°C.

Technical Context

The MAX1246ACPE+ uses successive-approximation register (SAR) architecture with an integrated track/hold circuit that acquires input signals in ≤1.5µs and supports both internal clock (up to 7.5MHz) and external clock (up to 2MHz) modes. Its analog front-end allows pseudo-differential sampling via CH0–CH3 and COM pins, with configurable input ranges (0V to VREF or ±VREF/2).

It implements a 4-wire serial interface compatible with SPI, QSPI, and MICROWIRE protocols (CPOL=0, CPHA=0), featuring MSB-first data output on SCLK falling edge and automatic power-up on CS assertion. The SHDN pin provides three-level control: full shutdown (low), internal compensation (high), or external compensation (floating) for the reference buffer.

Key Specifications

Pinout & Package

The MAX1246ACPE+ is housed in a 16-pin QSOP package (5.0mm × 6.2mm), occupying the same PCB footprint as an 8-pin SOIC - enabling 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 MAX11131AUT+, the MAX1246ACPE+ uniquely balances integrated 2.5V reference, MICROWIRE/SPI/QSPI flexibility, and QSOP-16 footprint - making it optimal for cost-sensitive, space-constrained, and multi-protocol legacy systems.

Availability

MAX1246ACPE+ is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered instruments requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX1246ACPE+ 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 MAX1246/MAX1247 family was engineered for low-power, multi-channel data acquisition in size- and battery-limited systems - emphasizing integrated functionality, flexible interface compatibility, and robust performance across temperature.

FAQ

What is the operating temperature range for the MAX1246ACPE+?

The MAX1246ACPE+ is specified for 0°C to +70°C ambient operation. This commercial-grade temperature range is validated per the device's AC and DC electrical characteristics tables and applies to all performance parameters including INL, offset error, and reference stability. The MAX1246ACPE+ variant uses the "C" grade suffix, confirming its compliance with this range - distinct from extended-grade variants like MAX1246BCPE (same range) or MAX1246ECEE (–40°C to +85°C).

Does the MAX1246ACPE+ require an external reference?

No, the MAX1246ACPE+ does not require an external reference. It integrates a factory-trimmed 2.5V reference with ±0.5% initial accuracy at +25°C and ±30ppm/°C temperature coefficient. The internal reference is enabled by default; REFADJ is used only for ±1.5% fine adjustment. External reference mode is disabled unless REFADJ is tied to VDD - a configuration not needed for standard operation of the MAX1246ACPE+.

Which serial interface protocols does the MAX1246ACPE+ support?

The MAX1246ACPE+ supports SPI, QSPI, and MICROWIRE protocols natively via its 4-wire interface (CS, SCLK, DIN, DOUT). It requires CPOL = 0 and CPHA = 0 for SPI/QSPI compatibility and transmits/receives data MSB-first on SCLK falling edge. No level-shifting or protocol translation logic is needed - direct connection to microcontrollers with these interfaces is fully supported per the device's timing diagrams and control-byte specification.

How does the SHDN pin function on the MAX1246ACPE+?

The SHDN pin on the MAX1246ACPE+ provides three distinct operating states: pulled low → full power-down (1µA ICC); pulled high → internal reference buffer in internal compensation mode; left floating → reference buffer in external compensation mode (requiring 4.7µF at VREF). This three-level control enables precise power management and reference configuration without additional control lines - a feature confirmed in the Pin Description section and Typical Operating Circuit of the MAX1246ACPE+ datasheet.

Can the MAX1246ACPE+ perform differential measurements?

Yes, the MAX1246ACPE+ supports true pseudo-differential measurements using CH0/CH1 and CH2/CH3 pairs. When configured via the SGL/DIF bit (bit 2 of control byte) = 0, the device samples the voltage difference between selected positive and negative inputs while maintaining COM as the analog ground reference. Input stability requirements (±0.5 LSB on IN−) and recommended 0.1µF bypass capacitor placement are explicitly defined in the Detailed Description section for reliable differential operation.