Analog Devices Inc./Maxim Integrated MAX6079ALA25+

Overview

MAX6079ALA25+ from Maxim Integrated is a low-noise, low-drift precision voltage reference IC delivering 2.500V output with ±0.08% initial accuracy, 6ppm/°C max temperature drift, and 4.8µV_P-P (0.1Hz–10Hz) noise - designed for high-accuracy industrial instrumentation and high-resolution ADC/DAC biasing in extended temperature environments.

For engineers reviewing the MAX6079ALA25+ datasheet, MAX6079ALA25+ pinout, MAX6079ALA25+ application, or MAX6079ALA25+ equivalent, this device supports Kelvin force/sense outputs, filter-enabled wideband noise reduction, and shutdown control - critical for metrology-grade signal chains requiring long-term stability and sub-ppm thermal hysteresis.

Technical Context

The MAX6079ALA25+ implements a bandgap-based reference core in a hermetically sealed 8-pin ceramic LCC package, enabling stable operation from −40°C to +125°C. Its dual ground architecture (GNDF/GNDS) and separate force (OUTF)/sense (OUTS) outputs support Kelvin connections to eliminate PCB trace resistance errors.

It integrates an active-high enable (EN) input for shutdown (I_SD < 6µA), a dedicated FILTER pin for optional 0.1µF capacitor placement to reduce 1kHz noise density from 60nV/√Hz to 30nV/√Hz, and supports capacitive loads from 0.1µF to 10µF while maintaining stability.

Key Specifications

Pinout & Package

MAX6079ALA25+ uses an 8-pin ceramic LCC (3mm × 3mm, lead-free/RoHS-compliant) with hermetic sealing for humidity- and time-stable performance. The package supports reflow soldering up to +260°C and features low θ_JA = 96.9°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision voltage reference applications.

Compared with ADR4525BRTZ-REEL7 and REF5025IDR, the MAX6079ALA25+ uniquely combines ceramic-package stability, integrated Kelvin sensing, and configurable wideband filtering - making it optimal for field-deployed instrumentation where environmental robustness and layout flexibility outweigh raw drift minimization.

Availability

MAX6079ALA25+ is available at Aetrix Electronics and suitable for high-accuracy industrial process control, precision instrumentation, and high-resolution ADC/DAC applications requiring stable component supply across extended temperature and long-life deployments.

Supply support for MAX6079ALA25+ 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 high-performance analog and mixed-signal ICs for industrial, automotive, and communications markets, emphasizing precision, reliability, and integration.

The MAX6079 series targets ultra-stable voltage referencing in harsh environments - specifically engineered for applications demanding sub-ppm thermal hysteresis, low 1/f noise, and hermetic packaging for decades-long calibration intervals.

FAQ

What is the maximum load current the MAX6079ALA25+ can source or sink?

The MAX6079ALA25+ guarantees ±10mA output current capability over −40°C to +125°C. It sources up to +10mA from OUTF and sinks up to −10mA into OUTF, with load regulation specified at 75–145µV/mA (source) and 80–160µV/mA (sink). This supports direct driving of medium-impedance ADC reference inputs and op-amp bias networks without external buffers. The MAX6079ALA25+ maintains regulation within ±0.08% accuracy across this full range.

Does the MAX6079ALA25+ require an output capacitor, and what value is recommended?

Yes, the MAX6079ALA25+ requires an output capacitor between 0.1µF and 10µF connected from OUTF to GNDS. A 0.1µF X7R ceramic capacitor placed adjacent to the OUTF pin is mandatory for stability and transient response. For rapidly varying loads, a parallel combination (e.g., 0.1µF + 4.7µF) reduces ESR and improves step-load immunity. The MAX6079ALA25+ becomes unstable outside this capacitance range.

How does the FILTER pin function, and what effect does it have on noise performance?

The FILTER pin accepts a 0.1µF capacitor to GNDS to reduce wideband noise - lowering 1kHz noise spectral density from 60nV/√Hz to 30nV/√Hz and improving PSRR above 1kHz. It does not affect DC accuracy or low-frequency drift. Larger capacitors yield diminishing returns. When unused, FILTER must be left floating - not tied to GND or V_IN. This feature is unique to the MAX6079ALA25+ among 2.5V ceramic references.

Can the MAX6079ALA25+ be used with a 3.3V supply, and what is its minimum operating voltage?

Yes, the MAX6079ALA25+ operates from 2.8V to 5.5V, making it fully compatible with 3.3V systems. Its dropout voltage is 110mV (typ) and 240mV (max) at 10mA load, so at 3.3V supply it delivers stable 2.500V output with ≥560mV headroom. Supply current remains nearly constant (160µA ±10%) across this range, simplifying power budgeting. The MAX6079ALA25+ maintains all specifications including drift and noise down to 2.8V.

What is the purpose of the separate GNDF and GNDS pins on the MAX6079ALA25+?

GNDF is the internal bandgap reference ground, while GNDS is the sense ground for the OUTS feedback loop - enabling true 4-wire Kelvin sensing. GNDF connects to local system ground near the IC; GNDS connects to the load's ground point. This separation cancels voltage drops across shared ground traces, preserving ±0.08% output accuracy even with 1Ω of PCB resistance between device and load. The MAX6079ALA25+ relies on this dual-ground architecture for metrology-grade performance.