Analog Devices Inc./Maxim Integrated MAX1278ETC+

Overview

MAX1278ETC+ from Maxim Integrated is a 12-bit, true-differential, single-supply 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 +4.75V to +5.25V analog supply and supports 1.8V–VDD digital logic via separate VL pin, enabling direct interfacing with low-voltage microcontrollers in motor control feedback loops.

For engineers reviewing the MAX1278ETC+ datasheet, MAX1278ETC+ pinout, MAX1278ETC+ application, or MAX1278ETC+ equivalent, this page delivers verified technical context, real-world timing behavior, differential acquisition constraints, power-down recovery timing, and validated alternative options for industrial signal acquisition systems.

Technical Context

The MAX1278ETC+ employs a successive-approximation register (SAR) architecture with an integrated true-differential track-and-hold (T/H), supporting bipolar input ranges (–VREF/2 to +VREF/2) and delivering 70dB SINAD at 525kHz input frequency. Its internal 4.096V reference remains enabled in partial power-down mode but is disabled in full power-down mode, requiring ≥2ms settling time after exit.

Conversion is initiated by a falling edge on CNVST, synchronized to SCLK (up to 28.8MHz); data appears MSB-first on DOUT starting at the 4th SCLK rising edge, with no pipeline delay and 16-clock-cycle total transfer (3 leading zeros + 12 data bits). Acquisition time is fixed at 104ns minimum, independent of source impedance below 12Ω.

Key Specifications

Pinout & Package

MAX1278ETC+ is housed in a 12-pin 3mm × 3mm TQFN package with exposed paddle (EP), rated for –40°C to +85°C operation. The EP is internally connected to GND and must be soldered to PCB ground plane for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8860IDRCT and AD7476ARTZ-REEL7, the MAX1278ETC+ uniquely integrates bipolar differential input, internal 4.096V reference, and three-tier power management in a 12-pin TQFN-enabling compact, self-contained, low-power signal acquisition without external support components.

Availability

MAX1278ETC+ is available at Aetrix Electronics and suitable for motor control feedback systems, industrial PLC analog input modules, and portable instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX1278ETC+ 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 infrastructure applications.

The MAX1276/MAX1278 family was engineered for high-speed, low-power, true-differential data acquisition in space- and power-constrained environments-targeting motor control, base station monitoring, and portable test equipment where internal reference integration and deterministic latency are critical.

FAQ

What is the input voltage range of the MAX1278ETC+?

The MAX1278ETC+ features a true-differential bipolar input range of –VREF/2 to +VREF/2, where VREF = 4.096V. This yields a usable differential input span of ±2.048V across AIN+ and AIN−. Absolute input voltage on each pin must remain within 0V to VDD (4.75V–5.25V), and internal protection diodes clamp inputs to GND –0.3V and VDD +0.3V.

Does the MAX1278ETC+ require an external reference?

No. The MAX1278ETC+ includes a factory-trimmed 4.096V internal reference accessible at the REF pin. It is active during normal and partial power-down modes, and disabled only in full power-down mode. A 0.01µF ceramic capacitor and 4.7µF tantalum capacitor to RGND are required for stability and noise suppression.

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

The MAX1278ETC+ 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 the same CNVST timing. Full power-down reduces supply current to ≤1µA and disables the internal reference, requiring ≥2ms recovery time before valid conversions resume.

Can the MAX1278ETC+ interface directly with a 1.8V microcontroller?

Yes. The MAX1278ETC+ supports 1.8V–VDD digital logic via its dedicated VL pin. When VL = 1.8V, the DOUT output high level is VL – 0.5V (≥1.3V), and input thresholds are 0.3×VL (0.54V) and 0.7×VL (1.26V), ensuring robust compatibility with 1.8V GPIOs without level shifters.

What is the minimum acquisition time for the MAX1278ETC+?

The MAX1278ETC+ has a guaranteed minimum acquisition time (tACQ) of 104ns, defined as the interval from the 14th SCLK rising edge to the CNVST falling edge. This value is fixed and unaffected by source impedance below 12Ω; for higher impedances, tACQ increases per tACQ ≥ 9 × (RS + 200Ω) × 16pF.