Analog Devices Inc. REF02AH

Overview

REF02AH from Analog Devices (formerly Linear Technology) is a precision 5V bandgap voltage reference with integrated temperature-sensing output, designed for high-stability analog signal conditioning and calibration circuits. It delivers ±0.3% initial accuracy, 5ppm/°C typical temperature coefficient over –55°C to +125°C, 10μV_P-P (0.1Hz–10Hz) output noise, and operates from 7V to 40V input. It is used in bridge excitation, precision DAC/ADC references, and trimmed industrial sensor front-ends.

For engineers reviewing the REF02AH datasheet, REF02AH pinout, REF02AH application, or REF02AH equivalent, key selection criteria include its guaranteed full-temperature-range TC (8.5ppm/°C max), dedicated TEMP pin (620mV @ 25°C, 2.1mV/°C), low 1.4mA max supply current, and TO-5 metal-can package for thermal stability and EMI resilience.

Technical Context

The REF02AH implements a curvature-compensated bandgap core with internal trimming to achieve tight initial tolerance and low drift across military-grade temperature range. Its TEMP pin provides a linear, factory-calibrated voltage proportional to absolute temperature-exclusively available on REF-02 variants and unused on REF-01.

Unlike standard references, it features dual regulation paths: one for stable 5V output under varying load (0–10mA), and another for low-noise, high-impedance temperature sensing (≤50nA sink/source on TEMP pin). Input line regulation is specified at 0.0001%/V over (V_OUT + 3V) ≤ V_IN ≤ 33V, minimizing supply-induced error in unregulated systems.

Key Specifications

Pinout & Package

REF02AH is housed in an 8-lead TO-5 metal can (H package), providing hermetic sealing, superior thermal conductivity (θ_JA = 150°C/W), and EMI shielding for high-precision analog environments. The case serves as GND (Pin 4).

Key Features

Applications

Equivalent & Alternatives

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

Compared with REF02AH, LT1019ACN8#PBF offers higher initial accuracy but lacks integrated temperature sensing, while REF02EH#PBF matches functionality and package but sacrifices military-temperature operation - making REF02AH uniquely suited for ruggedized, self-temperaturing analog systems.

Availability

REF02AH is available at Aetrix Electronics and suitable for precision DAC/ADC references, bridge excitation circuits, and calibrated temperature sensor nodes requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for REF02AH 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

Analog Devices (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, serving industrial, automotive, communications, and healthcare markets.

The REF-01/REF-02 family was engineered for applications demanding robust, low-drift voltage references with optional temperature telemetry - targeting test equipment, sensor signal chains, and calibration-critical embedded systems.

FAQ

What is the operating temperature range for REF02AH?

The REF02AH is specified for continuous operation from –55°C to +125°C, with all key parameters-including output voltage temperature coefficient (8.5ppm/°C max), line regulation, and load regulation-guaranteed across this full military-grade range. This makes REF02AH suitable for deployment in harsh environments such as aerospace avionics, downhole oilfield tools, and industrial control cabinets without thermal derating.

Does REF02AH provide a temperature output, and how is it used?

Yes, REF02AH includes a dedicated TEMP pin (Pin 3) that outputs a voltage linearly proportional to absolute temperature: 620mV at 25°C with a slope of 2.1mV/°C. This signal must be loaded with ≤50nA and capacitance ≤30pF - typically interfaced via unity-gain op-amp buffer into a high-impedance ADC input. It eliminates external temperature sensors in space-constrained or cost-sensitive designs requiring on-chip thermal monitoring.

What is the maximum load current REF02AH can source or sink?

The REF02AH can source up to 10mA and sink up to 0.3mA on its OUTPUT pin (Pin 6) while maintaining regulation within specifications. Load regulation is characterized at 0–10mA with a typical drift of 0.001%/mA. For higher current demands, an external buffer amplifier is recommended to preserve reference accuracy and thermal stability.

Is REF02AH pin-compatible with other members of the REF-01/REF-02 family?

Yes, all REF-01/REF-02 variants-including REF02AH, REF02EH#PBF, and REF01AH-share identical 8-lead TO-5 metal-can pinout (H package), including NC assignments and GND-as-case configuration. However, only REF-02 versions expose the TEMP pin function; REF-01 devices leave Pin 3 unconnected internally and should not be used where temperature output is required.

What are the key layout considerations for REF02AH in high-precision circuits?

For optimal performance, REF02AH requires a solid ground plane beneath the TO-5 can (Pin 4), a 0.1μF X7R ceramic capacitor placed within 2mm of the OUTPUT pin, and strict isolation of the TEMP pin from noisy traces or capacitive loads. Avoid routing digital or switching signals near Pin 3, and ensure the metal can is soldered directly to the PCB ground pour to maximize thermal dissipation and EMI rejection.