REF81 Temperature Controlled Precision Voltage Reference with 0.05ppm/°C

Temperature Drift and < 1ppm Stability

1 Features

• Buried zener core 7.6V output

• Industry standard fixed output voltage

– 1X gain: 2.5V, 4.096V, 5V

– 2X gain: 5V, 8.192V, 10V

• No external buffer for 1X and 2X gain output

• Industry standard fixed output initial accuracy

– 1X gain: ±0.05%

– 2X gain: ±0.1%

• Ultra-low temperature drift: 0.05ppm/°C

• Operating temperature range: 0°C to 70°C

• Excellent long term stability: 0.3ppm (1khr to 5khr)

• 1/f noise (0.1Hz to 10Hz) : 0.15ppmpk-pk

• Integrated heater with temperature stable indicator

• Input Voltage range: 10V to 16.5V

• Heater supply range: 10V to 42V

• Hermetically sealed ceramic package (20 pin

LCCC)

2 Applications

• Parametric measurement unit

• Lab and field instrumentation

• Precision weight scales

• Battery test equipment

• Digital multimeter

• Source measurement unit

• Data acquisition

3 Description

The REF81 device utilizes precision buried zener

core with integrated heater to generate stable

7.6V. The device further integrates precision resistor

dividers and a buffer to offer industry standard

voltage references to drive precision data converters.

Integrated temperature control with an internal

heater enables the reference voltage stay constant

irrespective

of

ambient

temperature

variations

and achieve extremely low temperature drift of

0.05ppm/°C. The integration of control loop, precision

resistances and buffer enables ease of design and

eliminates need of external precision components.

The REF81 family is available in a 20-pin LCCC

package. The LCCC package is a hermetically

sealed ceramic package that enables ultra low

long-term stability specification of 1ppm, critical for

applications that demand a longer operational window

without calibration. The package also offers excellent

immunity against humidity variation.

Device Information

PART NAME

PACKAGE (1)

BODY SIZE (NOM)

(2)

REF81

LCCC (20)

8.89mm × 8.89mm

(1)

For all available packages, see the orderable addendum at

the end of the data sheet.

(2)

The package size (length × width) is a nominal value and

includes pins, where applicable.

OP-STBL

T-SET

REF_GND

HEATM

Heater

Regulator

Buried Zener

Reference

RTOP

RBOT

+

–

VDD

BUFF_GND

R

GAIN_RFB

GAIN_RI

R

BUFF_OUT

+15V

10V

-15V

Stable Temp

Indicator

1X Gain

3.3V

0.5X Gain

REF81 Block Diagram (With Typical External Connections)

REF81

SLVSJJ3 – JULY 2025

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. ADVANCE INFORMATION for preproduction products; subject to change

without notice.