Analog Devices Inc./Maxim Integrated MAX111BEWE+T

Overview

MAX111BEWE+T from Maxim Integrated is a ±14-bit, 2-channel differential serial ADC operating from a single +5V supply, delivering 0.05% INL, 640µA active current, and 50Hz/60Hz rejection for precision low-frequency measurement in panel meters and weigh scales.

For engineers reviewing the MAX111BEWE+T datasheet, MAX111BEWE+T pinout, MAX111BEWE+T application, or MAX111BEWE+T equivalent, this device supports SPI/QSPI/MICROWIRE interfaces, offers auto-calibration under µP control, and targets battery-constrained or remote-sensing systems requiring stable ±1.5V differential input range with no external components.

Technical Context

The MAX111BEWE+T implements a first-order sigma-delta architecture with internal voltage-to-current conversion, integrator, comparator, and 1-bit DAC to generate PWM duty-cycle-modulated output proportional to input voltage. Its oversampling clock (fOSC) is selectable via RCSEL between internal RC oscillator (1.1–3.0 MHz) or external TTL/CMOS source.

Conversion results are output as 16-bit serial data (sign bit, overrange bit, 14 data bits in twos-complement), synchronized to SCLK falling edge, with BUSY signaling conversion start/end. Internal calibration corrects offset and gain errors under microprocessor command without external trim components.

Key Specifications

Pinout & Package

MAX111BEWE+T is housed in a 16-pin wide SO (SOIC-W) package with 1.27 mm pitch, 10.3 mm × 7.5 mm body, and gull-wing leads compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 14-bit serial ADC applications.

Compared with ADS1115IDGSR and MAX11602EEE+, the MAX111BEWE+T uniquely combines ±14-bit accuracy, dual differential inputs, 50/60Hz rejection, and zero-component operation in a compact SOIC package-making it optimal for cost-sensitive, low-power, mains-noise-prone measurement systems.

Availability

MAX111BEWE+T is available at Aetrix Electronics and suitable for panel meters, weigh scales, and temperature measurement systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX111BEWE+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, medical, and communications applications.

The MAX110/MAX111 family was engineered for high-resolution, low-power, serial-output data acquisition in space- and cost-constrained instrumentation-emphasizing self-calibration, noise immunity, and minimal external component count.

FAQ

What is the operating temperature range for MAX111BEWE+T?

The MAX111BEWE+T is specified for operation from –40°C to +85°C (industrial grade), as indicated by the 'E' suffix in the part number. This range is validated across all key parameters including INL, offset error, and supply current, ensuring reliable performance in harsh environmental conditions encountered in industrial control and outdoor instrumentation.

Does MAX111BEWE+T require external reference components?

No, the MAX111BEWE+T does not require external reference components. It accepts a differential reference input (REF+ and REF–) and operates with standard reference voltages such as 1.5V/0V. The device achieves ±0.05% INL without trimming or external calibration circuitry-its internal auto-calibration handles offset and gain correction under µP control.

How does the 50Hz/60Hz rejection work in MAX111BEWE+T?

The MAX111BEWE+T achieves 50Hz/60Hz rejection through inherent oversampling and digital filtering in its sigma-delta architecture. With fixed conversion timing (e.g., 81,920 clocks per conversion at 1MHz XCLK), the modulator integrates noise over integer multiples of line cycles, effectively canceling periodic interference without external hardware or firmware intervention.

Can MAX111BEWE+T interface directly with an Arduino or STM32 MCU?

Yes, the MAX111BEWE+T interfaces directly with Arduino and STM32 MCUs via standard SPI. Its SCLK, DIN, DOUT, and CS pins are TTL/CMOS-compatible and support DC–2MHz clock rates. BUSY can be connected to an interrupt pin to trigger data reads, and the device requires no special level-shifting or protocol translation-full 16-bit results are read in two 8-bit transfers.

What is the function of the RCSEL pin on MAX111BEWE+T?

The RCSEL pin selects the oversampling clock source: logic high enables the internal RC oscillator (1.1–3.0 MHz), while logic low routes an external clock to XCLK. When RCSEL = VDD, XCLK becomes an output driven by the internal oscillator; when RCSEL = GND, XCLK is an input accepting TTL/CMOS signals-enabling flexible timing control without external crystal.