Analog Devices Inc./Maxim Integrated MAX1286ETA+T

Overview

MAX1286ETA+T from Maxim Integrated is a 12-bit, 150ksps successive-approximation ADC with true-differential analog input (AIN+/AIN−), single +5V supply operation (4.75–5.25V), and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface. It features 1.4µs acquisition time, ±1.0 LSB INL, and 0.5mW power consumption at full rate - optimized for precision portable data acquisition where space and battery life are critical.

For engineers reviewing the MAX1286ETA+T datasheet, MAX1286ETA+T pinout, MAX1286ETA+T application, or MAX1286ETA+T equivalent, this device supports low-noise true-differential sampling up to 1 MHz small-signal bandwidth, auto-shutdown (0.2µA), and software-configurable unipolar/bipolar conversion - key selection criteria for sensor front-ends in handheld instrumentation and industrial monitoring systems.

Technical Context

The MAX1286ETA+T implements a SAR architecture with an on-chip track-and-hold (T/H) that enters tracking on CNVST rising edge and holds on falling edge. Its differential input stage accepts signals from 0 to VREF (unipolar) or ±VREF/2 (bipolar), with internal switched-capacitor DAC and comparator enabling precise 12-bit conversion without external timing components.

Conversion is clocked by an internal 4MHz oscillator (±10% tolerance), eliminating need for external clock source; data is output MSB-first on DOUT synchronized to SCLK falling edge, compatible with standard microcontroller SPI peripherals configured as master with CPOL=CPHA=0.

Key Specifications

Pinout & Package

MAX1286ETA+T is housed in an 8-pin TDFN-EP package (3mm × 3mm, 0.75mm height) with exposed pad (EP) for thermal enhancement and grounding. Pin 1 is marked with top-side laser code "+AFR".

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7816U and AD7476ARTZ-REEL7, MAX1286ETA+T uniquely combines true-differential input, integrated clock, AutoShutdown, and TDFN packaging - delivering lowest system-level power and smallest PCB area for portable precision measurement.

Availability

MAX1286ETA+T is available at Aetrix Electronics and suitable for portable temperature monitors, flowmeters, and touch screens requiring stable component supply across industrial and medical product lifecycles.

Supply support for MAX1286ETA+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) designs precision analog, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The MAX1286–MAX1289 family targets ultra-low-power, space-constrained data acquisition systems - delivering high-resolution ADC functionality in sub-3mm² packages without sacrificing dynamic performance or ease of microcontroller interfacing.

FAQ

What supply voltage range does the MAX1286ETA+T support?

The MAX1286ETA+T operates from a single +4.75V to +5.25V supply. This range ensures compatibility with standard 5V logic systems and regulated 5V rails. Operation outside this window risks parametric degradation or damage; the absolute maximum rating is +6V. The device draws 245µA at 150ksps under these conditions, making it suitable for both mains-powered and battery-backed instrumentation using MAX1286ETA+T.

Does the MAX1286ETA+T require an external clock source?

No, the MAX1286ETA+T uses an internal 4MHz oscillator for conversion timing, eliminating need for external crystal or clock generator. This reduces BOM cost and PCB area while ensuring deterministic 3.7µs max conversion time. The serial interface clock (SCLK) is supplied externally up to 8MHz, but the core SAR conversion is fully self-timed - a key advantage of MAX1286ETA+T in resource-constrained embedded systems.

How does the MAX1286ETA+T handle unipolar versus bipolar input configurations?

The MAX1286ETA+T selects unipolar or bipolar mode via CNVST pulse sequencing: a single high pulse configures unipolar (0 to VREF), while a high–low–high pulse sequence configures bipolar (±VREF/2). Output format is straight binary (unipolar) or two's complement (bipolar). No registers or commands are involved - this hardware-based mode selection simplifies firmware and ensures deterministic behavior in MAX1286ETA+T implementations.

What is the purpose of the exposed pad (EP) on the MAX1286ETA+T TDFN package?

The exposed pad (EP) on the MAX1286ETA+T serves dual thermal and electrical functions: it must be soldered to the PCB ground plane to lower thermal resistance (θJA ≈ 67°C/W) and provide low-impedance analog ground return. Leaving EP unconnected degrades PSR by >10dB and increases junction temperature - directly impacting MAX1286ETA+T long-term reliability and AC performance in continuous operation.

Can the MAX1286ETA+T interface directly with a PIC16 microcontroller's SSP module?

Yes, the MAX1286ETA+T is fully compatible with PIC16/PIC17 SSP modules in SPI master mode. Configure SSPCON with CKP=0 and SSPM=0x01 (FOSC/16), and SSPSTAT with CKE=1 and SMP=0. Two consecutive 8-bit reads retrieve the full 12-bit result, with DOUT transitioning on SCLK falling edge. This proven interoperability simplifies firmware development and validates MAX1286ETA+T for cost-sensitive 8-bit MCU platforms.