Analog Devices Inc./Maxim Integrated MAX6126A21+

Overview

MAX6126A21+ from Maxim Integrated is an ultra-high-precision, ultra-low-noise series voltage reference delivering 2.048V output with ±0.06% initial accuracy, 3ppm/°C max temperature coefficient (–40°C to +125°C), and 1.3μV_P-P (0.1Hz–10Hz) flicker noise. It operates from 2.7V to 12.6V supply, supports ±10mA load current, and features force/sense outputs for remote sensing in high-resolution ADC/DAC biasing and precision current sources.

For engineers reviewing the MAX6126A21+ datasheet, MAX6126A21+ pinout, MAX6126A21+ application, or MAX6126A21+ equivalent, this page delivers verified specifications, package mapping, real-world use cases, and validated alternative options - all aligned to the A grade, 8-pin μMAX® package with 2.048V output and automotive-grade –40°C to +125°C operation.

Technical Context

The MAX6126A21+ employs curvature-corrected bandgap architecture with laser-trimmed thin-film resistors to achieve 3ppm/°C tempco and ±0.06% initial accuracy over full automotive temperature range. Its proprietary low-noise design separates flicker and wideband noise paths, enabling 1.3μV_P-P (0.1Hz–10Hz) and 60nV/√Hz (1kHz, no NR cap) without elevated quiescent current.

It integrates independent force (OUTF) and sense (OUTS) outputs plus ground-sense (GNDS) for Kelvin connections, eliminating IR drop errors in precision current sourcing and high-accuracy reference distribution. The NR pin accepts a 0.1μF capacitor to reduce wideband noise to 35nV/√Hz and improve AC PSRR.

Key Specifications

Pinout & Package

MAX6126A21+ is housed in an 8-pin μMAX® package (3mm × 3mm, 0.8mm height), optimized for space-constrained automotive and industrial PCBs. Pin 1 is NR (Noise Reduction), Pin 2 is IN, Pin 3 is GND, Pin 4 is GNDS, Pins 5 & 8 are internally connected (NC), Pin 6 is OUTS, and Pin 7 is OUTF.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6126A21+, ADR4520BRZ offers tighter initial accuracy but sacrifices Kelvin sensing and noise-reduction flexibility, while REF5020AIDR trades lower noise performance and higher supply current for TI's production support and extended qualification.

Availability

MAX6126A21+ is available at Aetrix Electronics and suitable for high-resolution data acquisition, precision current sources, digital voltmeters, and ATE equipment requiring stable component supply across automotive and industrial environments.

Supply support for MAX6126A21+ 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 demanding industrial, automotive, and communications applications.

The MAX6126 family targets ultra-high-accuracy, ultra-low-noise voltage referencing in metrology-grade instruments and safety-critical systems where long-term stability and thermal robustness are non-negotiable.

FAQ

What is the maximum dropout voltage specification for MAX6126A21+ at 10mA load?

The MAX6126A21+ has a maximum dropout voltage of 200mV at 10mA load current, defined as the minimum (VIN – VOUT) differential required to maintain output regulation within 0.1% of nominal 2.048V. This allows operation down to 2.248V supply, supporting low-voltage battery-powered designs without external LDOs.

Does MAX6126A21+ require an external resistor like shunt references?

No, MAX6126A21+ is a series-mode voltage reference and does not require an external current-setting resistor. Its 380μA quiescent supply current is virtually independent of input voltage (±2μA/V max variation), simplifying design and improving efficiency compared to two-terminal shunt references.

How does the NR pin on MAX6126A21+ affect noise performance?

The NR pin on MAX6126A21+ accepts a 0.1μF capacitor to reduce wideband noise from 60nV/√Hz to 35nV/√Hz at 1kHz and improve AC power-supply rejection. With the capacitor, 0.1Hz–10Hz flicker noise drops to 0.9μV_P-P, enhancing dynamic measurement fidelity in sensitive analog front-ends.

Can MAX6126A21+ drive a 10μF output capacitor without instability?

Yes, MAX6126A21+ is stable with output capacitance from 0.1μF to 10μF - explicitly guaranteed in the datasheet. For fast transient loads, pairing 10μF (bulk) with 0.1μF (high-frequency bypass) near OUTF improves step-load response while maintaining phase margin.

What is the purpose of GNDS and how does it differ from GND on MAX6126A21+?

GNDS on MAX6126A21+ is a dedicated ground-sense terminal that connects to the load-side ground point, enabling Kelvin compensation for ground-return IR drop. Unlike GND (power ground), GNDS isolates the reference regulation loop from load-current-induced ground shifts, preserving accuracy in high-current precision circuits.