Analog Devices Inc./Maxim Integrated MAX1278ETC+T

Overview

MAX1278ETC+T from Maxim Integrated is a 12-bit, true-differential, serial-output analog-to-digital converter (ADC) with internal 4.096V reference, 1.8Msps sampling rate, ±1.25 LSB INL, and bipolar input range of ±2.048V. It operates from a single +4.75V to +5.25V analog supply and supports 1.8V–VDD digital logic via dedicated VL pin, enabling direct interfacing with low-voltage microcontrollers in motor control and industrial data acquisition systems.

For engineers reviewing the MAX1278ETC+T datasheet, MAX1278ETC+T pinout, MAX1278ETC+T application, or MAX1278ETC+T equivalent, key selection criteria include its bipolar differential input architecture, SPI/QSPI/MICROWIRE-compatible 3-wire interface, full-power-down current ≤1µA, 70dB SINAD at 525kHz, and TQFN-12 package with exposed paddle for thermal performance.

Technical Context

The MAX1278ETC+T employs a successive-approximation register (SAR) architecture with an internal true-differential track-and-hold (T/H), enabling high-fidelity sampling of bipolar signals without external level-shifting circuitry. Its conversion is initiated by a CNVST falling edge and clocked by SCLK, requiring exactly 16 cycles for full 12-bit output plus three leading zeros in MSB-first format.

It features dual power-down modes: partial power-down reduces IDD to 2mA while retaining reference stability, and full power-down cuts total supply current to ≤1µA with 2ms reference recovery time. The internal 4.096V reference is trimmed and temperature-compensated (±50ppm/°C), sourced from REF and usable externally up to 2mA.

Key Specifications

Pinout & Package

The MAX1278ETC+T is housed in a 12-pin 3mm × 3mm TQFN package with exposed paddle (EP), rated for –40°C to +85°C operation. Thermal performance is enhanced by internal EP-to-GND connection; PCB layout requires soldering EP to a solid ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8860IDRCT and AD7403BRIZ-RL7, the MAX1278ETC+T offers the only combination of integrated 4.096V reference, true-differential bipolar input, 1.8Msps throughput, and ≤1µA full power-down-making it uniquely suited for compact, battery-aware, cost-sensitive industrial edge nodes.

Availability

MAX1278ETC+T is available at Aetrix Electronics and suitable for motor control feedback, industrial data acquisition, portable test equipment, and communications baseband applications requiring stable component supply, extended temperature operation, and RoHS-compliant packaging.

Supply support for MAX1278ETC+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 industrial, automotive, and communications markets.

The MAX1276/MAX1278 product line delivers low-power, high-speed SAR ADCs with integrated references and differential inputs-engineered specifically for space-constrained, noise-immune data acquisition in motor drives and portable instrumentation.

FAQ

What is the input voltage range of the MAX1278ETC+T?

The MAX1278ETC+T has a true-differential bipolar input range of AIN+ – AIN– = ±VREF/2 = ±2.048V, with absolute input voltage limits of 0V to VDD on each pin. This allows direct digitization of AC-coupled sensor outputs or center-biased signals without external level-shifting circuitry-critical for maintaining signal integrity in motor current sensing applications using the MAX1278ETC+T.

Does the MAX1278ETC+T require an external reference?

No, the MAX1278ETC+T includes a factory-trimmed 4.096V internal reference accessible at the REF pin, with ±10mV initial accuracy and ±50ppm/°C temperature coefficient. The reference remains active in normal and partial power-down modes, and is disabled only in full power-down mode-eliminating the need for external reference components and simplifying system design around the MAX1278ETC+T.

How does the MAX1278ETC+T enter full power-down mode?

The MAX1278ETC+T enters full power-down mode by executing the partial power-down sequence twice: pull CNVST high after the 3rd but before the 14th SCLK rising edge, wait ≥14 SCLK cycles, then repeat. This reduces total supply current to ≤1µA. Recovery requires ≥2ms for the internal reference to settle before the next valid conversion-essential timing to observe when designing low-power wake-up sequences with the MAX1278ETC+T.

What digital interfaces are compatible with the MAX1278ETC+T?

The MAX1278ETC+T supports SPI, QSPI, and MICROWIRE protocols via its 3-wire serial interface (SCLK, CNVST, DOUT), operating with all four CPOL/CPHA combinations. It interfaces directly with TI TMS320C54x DSPs and most microcontrollers' synchronous serial ports without glue logic-enabling rapid integration into existing firmware stacks that already support standard serial peripheral interfaces using the MAX1278ETC+T.

What is the significance of the VL pin on the MAX1278ETC+T?

The VL pin on the MAX1278ETC+T supplies power to the digital interface independently from VDD, accepting +1.8V to VDD. This allows direct connection to 1.8V, 2.5V, 3.3V, or 5V logic without level shifters-reducing component count, board area, and signal integrity risks in mixed-voltage systems. It ensures robust DOUT timing and CNVST/SCLK threshold compatibility across diverse host processors interfacing with the MAX1278ETC+T.