Hi, I'm working on a design for measuring low voltage(+/- 50mV) with high accuracy. I'm using the MSP432 for its 14 bit ADC and I wanted to improve the accuracy by using a precision voltage reference. I'm testing my design with an AD589KH as my voltage reference and am powering it with the 5v rail from the board and a 1k resistor to drop the voltage. I can get the 1.225v that I'm expecting, but when I connect it to the Vref+ pin and ground to the Vref- pin my reference voltage drops to .335v. This resulted in all of my ADC readings returning my max expected voltage of 1.225 when I mapped my digital readings back to a voltage. I'm using Energia to program it and am seeing about 6mV of error from an Agilent handheld DMM when using the internal reference. Another issue I'm seeing is that when my ADC pins are connected to my breadboard with a test power supply turned off, I'm expecting to see 0v, but instead I see between .5v and 1v. When the supply is turned on that offset seems to disappear. My board also gets hot when in use, which I've seen in other threads so I'm not sure if that's is contributing to the issues I'm experiencing or not. Thanks for the support.
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