Analog Devices Inc./Maxim Integrated MAX1278CTC+

Overview

MAX1278CTC+ 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 MAX1278CTC+ datasheet, MAX1278CTC+ pinout, MAX1278CTC+ application, or MAX1278CTC+ equivalent, this page delivers verified technical context, real-world design implications of its differential track/hold architecture, SPI/QSPI/MICROWIRE timing compliance, power-down modes (2mA partial / 1µA full), and bipolar transfer function - all confirmed for the exact MAX1278CTC+ variant in 12-pin TQFN.

Technical Context

The MAX1278CTC+ employs a successive-approximation register (SAR) architecture with an internal true-differential track-and-hold (T/H), enabling high-fidelity digitization of bipolar signals without external signal conditioning. Its T/H acquires input within 104ns and supports up to 20MHz small-signal bandwidth, allowing undersampling of high-frequency transients.

Conversion is initiated by a falling edge on CNVST, synchronized to SCLK (up to 28.8MHz); data appears MSB-first on DOUT after the 4th SCLK rising edge, requiring exactly 16 clock cycles for full 12-bit output plus 3 leading zeros. The device maintains internal reference stability during partial power-down but disables it in full power-down mode, requiring ≥2ms recovery before valid conversion.

Key Specifications

Pinout & Package

MAX1278CTC+ is housed in a 12-pin 3mm × 3mm TQFN package with exposed paddle (EP), rated for -40°C to +85°C operation. Pin 1 is AIN-, pin 12 is AIN+, and EP is internally connected to GND for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8860IDRCT and AD7403BRIZ-RL7, the MAX1278CTC+ uniquely combines 1.8Msps speed, true-differential bipolar input, integrated 4.096V reference, and SPI/QSPI compatibility in a single 12-pin TQFN - making it optimal for cost-sensitive, space-constrained, real-time embedded control where isolation or ultra-high resolution is unnecessary.

Availability

MAX1278CTC+ is available at Aetrix Electronics and suitable for motor control, industrial data acquisition, and portable instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX1278CTC+ 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 applications.

The MAX1276/MAX1278 product line delivers low-power, high-speed SAR ADCs with integrated references and differential inputs - engineered specifically for real-time embedded systems demanding accuracy, speed, and minimal external components.

FAQ

What is the exact analog input voltage range supported by the MAX1278CTC+?

The MAX1278CTC+ supports a true-differential bipolar input range of –VREF/2 to +VREF/2, where VREF = 4.096V. This yields a full-scale differential input span of ±2.048V (–2.048V to +2.048V) between AIN+ and AIN–. Absolute input voltages must remain within 0V to VDD (4.75V–5.25V) to avoid damage or conversion errors.

Does the MAX1278CTC+ require external components for stable operation?

Yes - the MAX1278CTC+ requires specific bypass capacitors: 0.01µF + 4.7µF from REF to RGND; 0.01µF + 10µF from VDD to GND; and 0.01µF + 10µF from VL to GND. These ensure reference stability, analog supply decoupling, and digital noise suppression. Omitting them degrades INL, SINAD, and power-down recovery.

How does the MAX1278CTC+ enter and exit full power-down mode?

The MAX1278CTC+ enters full power-down mode by executing the partial power-down sequence twice consecutively: pull CNVST high after the 3rd but before the 14th SCLK rising edge, then repeat. To exit, drive CNVST low, wait ≥14 SCLK cycles, then drive CNVST high. Allow ≥2ms for internal reference to settle before first conversion.

Is the MAX1278CTC+ compatible with standard SPI microcontrollers?

Yes - the MAX1278CTC+ supports all four SPI modes (CPOL/CPHA combinations) and interfaces directly with STM32, NXP Kinetis, and Renesas RA series MCUs. It outputs 12-bit two's complement data MSB-first with three leading zeros, requiring no software bit-shifting beyond standard SPI receive buffer handling.

What is the guaranteed INL performance of the MAX1278CTC+ over temperature?

The MAX1278CTC+ guarantees ±1.25 LSB integral nonlinearity over its full operating temperature range of –40°C to +85°C. This specification is tested and ensured across temperature, not just at +25°C, and applies to the exact MAX1278CTC+ variant in the 12-pin TQFN package.