Analog Devices Inc./Maxim Integrated MAX11040KGUU+T

Overview

The MAX11040KGUU+T from Maxim Integrated is a 24-bit, 4-channel, simultaneous-sampling sigma-delta analog-to-digital converter (ADC) with cascading capability for up to 32 synchronized channels. It delivers 117dB SNR at 1ksps and 106dB SNR at 16ksps, operates from a single +3V supply, features ±6V overvoltage-protected differential inputs, and supports programmable output data rates from 0.25ksps to 64ksps. It is used in high-accuracy energy metering and multiphase power monitoring systems.

For engineers reviewing the MAX11040KGUU+T datasheet, MAX11040KGUU+T pinout, MAX11040KGUU+T application, or MAX11040KGUU+T equivalent, this page provides verified technical context, real-world design meanings of key specs, validated pin functions, confirmed alternative parts with documented differences, and supply-chain support details specific to industrial-grade power measurement deployments.

Technical Context

The MAX11040KGUU+T integrates four independent sigma-delta modulators and digital decimation filters, each with fully differential analog inputs and buffered reference outputs (REF0–REF3). Its internal 24.576MHz crystal oscillator-enabled via XTALEN bit-feeds a modulator clock derived by dividing XIN by 8, enabling precise timing control across cascaded devices.

It implements a programmable sampling phase (0–333μs in 1.33μs steps) per channel to compensate for input-phase shifts from transformers or filters, and uses a SYNC input to align conversion timing across multiple devices using an external timing source-critical for synchronized sampling in multiphase power systems.

Key Specifications

Pinout & Package

MAX11040KGUU+T is housed in a 38-pin TSSOP package (JEDEC MO-153), with exposed thermal pad (not electrically connected), rated for -40°C to +105°C operation. Pin layout separates analog (AGND, AVDD, AINx±, REFx) and digital (DGND, DVDD, SCLK, DIN/DOUT, CASCIN/CASCOUT) domains to minimize noise coupling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-accuracy, multi-channel sigma-delta ADC applications.

Compared with AD7606C-24 and ADS131M04, the MAX11040KGUU+T uniquely combines 24-bit resolution, integrated crystal oscillator, per-channel programmable sampling phase, and hardware-supported daisy-chaining-making it the only option that satisfies simultaneous 4-channel sampling with transformer-induced phase error correction in a single IC.

Availability

MAX11040KGUU+T is available at Aetrix Electronics and suitable for power-protection relay equipment, multiphase power systems, and industrial data-acquisition systems requiring stable component supply across extended product lifecycles.

Supply support for MAX11040KGUU+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 and mixed-signal ICs for industrial, automotive, and communications applications, with emphasis on high-reliability, low-power, and feature-rich solutions.

The MAX11040K product line targets high-accuracy energy measurement and power quality monitoring, integrating synchronized sampling, fault resilience, and system-level timing features to simplify compliance with IEC 62053 and IEEE 1459 standards.

FAQ

What is the maximum number of MAX11040KGUU+T devices that can be cascaded, and how is synchronization maintained?

The MAX11040KGUU+T supports cascading up to eight devices using CASCIN/CASCOUT signals, enabling 32 simultaneous sampling channels. Synchronization is maintained through the SYNC input, which aligns conversion timing across all devices-even those using independent crystal oscillators-by propagating a common edge-triggered signal. This ensures sub-microsecond inter-device phase alignment critical for multiphase power calculations. The MAX11040KGUU+T's internal logic guarantees deterministic latency across the chain.

Does the MAX11040KGUU+T support both internal and external reference configurations, and what are the voltage ranges?

Yes, the MAX11040KGUU+T supports dual reference modes: internal 2.5V reference (±50ppm/°C drift, 3µV RMS noise) sourced from REFIO, or external reference applied to REFIO within 2.3V–2.7V. In internal mode, REFIO outputs 2.4V–2.6V (typical 2.5V) with 1kΩ output impedance; in external mode, REFIO sinks/source up to 200µA. Each ADC channel has its own buffered reference (REF0–REF3), bypassed with 1µF to AGND, ensuring channel-to-channel isolation.

How does the programmable sampling phase in the MAX11040KGUU+T improve accuracy in power metering applications?

The MAX11040KGUU+T provides per-channel programmable sampling phase (0–333μs in 1.33μs steps) to compensate for fixed group delay introduced by external components like current transformers (CTs) or anti-aliasing filters. This correction ensures true time-aligned sampling across all four channels-essential for accurate calculation of active/reactive power, symmetrical components, and harmonic distortion in IEC 61000-4-30 Class A meters. Without this feature, phase mismatch would introduce systematic errors exceeding 0.1% at 50Hz.

What are the absolute maximum ratings for analog input voltage on the MAX11040KGUU+T, and how does overvoltage protection operate?

The MAX11040KGUU+T analog inputs (AINx+/−) tolerate −6V to +6V differential voltage continuously without damage, exceeding typical ±2.2V full-scale range. Overvoltage protection activates when either AINx+ or AINx− exceeds ±2.25V to ±2.65V relative to AGND (VPFT/VNFT thresholds), pulling the FAULT pin low within 2.5μs. The protection circuitry remains functional across the full −40°C to +105°C temperature range and requires no external components-enabling direct interface to unprotected CT/VT outputs in utility substations.

Can the MAX11040KGUU+T operate without an external crystal, and what clock options are supported?

Yes, the MAX11040KGUU+T can operate without an external crystal by disabling the internal oscillator (XTALEN = 0) and driving XIN with an external 24.576MHz CMOS clock. When enabled, the internal oscillator supports crystals with ≤30Ω ESR (e.g., RXD MP35) between XIN and XOUT. CLKOUT provides a buffered version of the oscillator output, capable of driving up to eight loads. The modulator clock is always XIN/8, ensuring consistent oversampling ratio regardless of clock source.