Analog Devices Inc./Maxim Integrated MX581TH

Overview

MX581TH from Maxim Integrated is a three-terminal, temperature-compensated bandgap voltage reference delivering a precision 10.000V ±10mV output across –55°C to +125°C, with max tempco of 15ppm/°C, supply current of 1.0mA (max), and 10mA output sourcing/sinking capability. It operates from 12.5V to 30V input and is used in high-reliability data acquisition systems requiring military-grade stability.

For engineers reviewing the MX581TH datasheet, MX581TH pinout, MX581TH application, or MX581TH equivalent, key selection criteria include its TO-39 metal-can package, ±10mV initial error at extended temperature, 15ppm/°C drift, short-circuit protection, and compatibility with 12-bit ADCs/DACs in harsh-environment instrumentation.

Technical Context

The MX581TH implements a laser-trimmed bandgap core with internal buffer amplifier, enabling full accuracy without external components over its full –55°C to +125°C operating range. Its output maintains regulation under load currents from –10mA to +10mA and exhibits 50µV_P-P (0.1Hz–10Hz) low-frequency noise.

It features dual-mode operation: standard three-terminal configuration for +10V reference, and two-terminal zener-like biasing for –10V generation (with temperature-limited –55°C to +85°C operation). Turn-on settling to 0.1% occurs in 200µs, and line regulation is 0.002%/V (15V–30V).

Key Specifications

Pinout & Package

MX581TH uses a hermetically sealed 3-pin TO-39 metal can package with case grounded. Pin 1 = +VS, Pin 2 = GND (case-connected), Pin 3 = VOUT. The metal case provides EMI shielding and thermal conduction to heatsink or chassis.

Key Features

Applications

Equivalent & Alternatives

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

Compared with REF5010IDR and ADR441BRZ, the MX581TH uniquely combines hermetic TO-39 packaging, –55°C start-up capability, and ±10mA bidirectional drive - making it irreplaceable in aerospace and downhole applications where environmental survivability and output flexibility are non-negotiable.

Availability

MX581TH is available at Aetrix Electronics and suitable for aerospace data acquisition, downhole instrumentation, and military radar signal processing requiring stable component supply across extended temperature extremes and long product lifecycles.

Supply support for MX581TH 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 MX581TH belongs to Maxim's high-stability voltage reference product line, engineered specifically for military, aerospace, and oilfield instrumentation where hermetic packaging, wide temperature operation, and zero-external-component simplicity are mandatory.

FAQ

What is the maximum input voltage rating for the MX581TH?

The MX581TH has an absolute maximum input voltage of +40V relative to GND. Operation above this level risks permanent damage. For reliable long-term use, the recommended input range remains 12.5V to 30V as specified in the electrical characteristics table. Exceeding 30V may degrade line regulation performance and increase junction temperature beyond safe limits, especially in the TO-39 package with its 150°C/W thermal resistance.

Does the MX581TH require external capacitors for stability?

No, the MX581TH does not require external capacitors for basic stability across its full –55°C to +125°C operating range. Its internal compensation ensures unconditional stability with purely resistive loads. However, when sinking current, a minimum 10nF load capacitance is required for proper operation, as stated in the datasheet's Output Current section. This capacitance stabilizes the output stage during sink-mode transitions.

Can the MX581TH generate a negative 10V reference?

Yes, the MX581TH can be configured as a two-terminal device to produce a –10V reference by connecting +VS and VOUT to analog ground and biasing the GND pin through a resistor to a negative supply. However, this configuration restricts operation to –55°C to +85°C, not the full –55°C to +125°C range, and requires maintaining 1mA–5mA reference current. The output voltage is typically ~2mV higher than in standard positive configuration.

What is the thermal resistance of the MX581TH TO-39 package?

The MX581TH in the TO-39 metal-can package has a thermal resistance of 150°C/W (junction-to-ambient). This value assumes standard mounting on a PCB with minimal copper pour. Derating begins at +60°C ambient, reducing maximum power dissipation by 8.7mW per °C above that point. For high-temperature applications, direct thermal bonding of the case to a heatsink or chassis is recommended to maintain junction temperature below +150°C.

How does the MX581TH's 10mA bidirectional output benefit circuit design?

The MX581TH's ability to source and sink up to 10mA simplifies interface design for components requiring active pull-down (e.g., certain comparator inputs) or current-driven references (e.g., some DACs). It eliminates external transistors or op-amps in current-limiting, threshold-detection, and high-current reference buffer applications - reducing component count, board space, and failure points while maintaining precision across temperature.