Product Name: REF81 buried Zener precision voltage reference

Manufacturer: Texas Instruments

Product Category: Test, Measurement, Sensors and Software

Supporting Documentation (if available)

The REF81 is the industry's first temperature-controlled buried Zener precision voltage reference to deliver an ultra-low 0.05 ppm/°C temperature drift and less than 1 ppm long-term stability, enabling test and measurement equipment and precision instrumentation to measure electrical parameters with greater accuracy while extending calibration intervals from months to years. As semiconductor manufacturing complexity increases and demand for high-precision automated test equipment accelerates, the need for voltage references that maintain accuracy over longer periods without recalibration has never been greater. TI's REF81 does not require external heating circuits or frequent recalibration, and can maintain exceptional stability with long-term drift of only 3 ppm in the first 1,000 hours and 0.3 ppm from 1,000 to 5,000 hours, with less than 2% variation in performance across temperature. This integrated thermal control enables up to 10 times better long-term accuracy than typical industry standards.

The REF81 can accurately deliver a precise 10V output from a 5V supply while maintaining noise performance of 0.12 ppm peak-to-peak (0.1 Hz to 10 Hz). Additionally, the REF81 incorporates an internal heater, buffer and precision resistor divider in a single package, eliminating external thermal control circuits and achieving very low drift in the high-precision signal path, enabling designs to achieve faster calibration cycles and reduced bill of materials costs. With an integrated buffer, configurable output voltages and support for multiple industry-standard interfaces, designers can reduce system complexity by simplifying the signal chain compared to discrete solutions. Applications include parametric measurement units, lab and field instrumentation, precision weight scales and battery test equipment. Other applications include digital multimeters, source measurement units, data acquisition systems, semiconductor automated test equipment and industrial metrology systems used in precision calibration of electrical measurements and dimensional accuracy standards.

Supporting documents:
- Product URL: https://www.ti.com/product/REF81
- REF81 data sheet: https://www.ti.com/lit/ds/symlink/ref81.pdf
- Technical article: The benefits of extreme precision from buried Zener technology in calibration
- REF81EVM evaluation module: https://www.ti.com/tool/REF81EVM
- Reference design: Low-noise, highly linear digital multimeter and data acquisition signal chain reference design (TIDA-010970): https://www.ti.com/tool/TIDA-010970
- Portfolio overview: Series voltage references: https://www.ti.com/product-category/power-management/voltage-references/series/overview.html