REF3312: REF3312

Hello,

I am interested in a Precision and Stable voltage reference that could be used as a calibration source in college instrumentation lab. The accuracy value is less critical than stability, as the device will be used repeatedly over time. The device may initially be calibrated by comparing against a known precise measuring device (DMM). Sending the unit to a calibration service or getting a precision 6.5/7.5 digit Agilent meter is out of budget.

I will also like to enclose the device in a temperature controlled small chamber similar to temperature controlled crystal oscillator. The temperature control system will be an inhouse design using one of TI's precision solid state temperature sensor. The estimated the controlled temperature will be about 45 degree C. A small MCU will be used to control the enclosure temperature. The MCU will be placed outside the enclosure so as not to add to thermal load. A second TI reference IC can be used to calibrate the temperature controlled unit to ensure an accuracy of 0.15% (for REF3312).

Ref3312 has a stated initial accuracy of 0.15%. It has just been selected as a starting point and can be substituted with another voltage reference IC, if the newer device will provide better performance. The exact voltage is also not critical and it can be anywhere in range 1.0V to 5.0V. Since the device will be used in lab, power for temperature control is not an issue. Summarizing, It will be greatly appreciated for your advice on the following:

• Best temperature reference for stability
• Temperature sensor with digital output (IIC or SPI) for its inherent accuracy and stability
• Tips on enclosure design.

Thanks and Kind Regards,

Sudhir Gupta