09-23-2020 09:52 AM
Hi Engineers,
I have a question on instrument accuracy. Could someone help me in understanding how to choose a instrument for the below DC Voltage Regulator voltage measurements.
Typical O\P voltage of regulator at no load = 5V.
Load Regulation (0 to 100mA) is 0V to 0.05V
I wanted to measure the o\p voltage of a regulator. I can either measure using SMU (0.02% + 200uA Accuracy at 6V operating range) or DMM( Six and Half digit). As we already know DMM gives more accurate and precise measurement. But do I need that much accuracy for the above measurements? (Yes or No: Please provide the reason)
09-23-2020 10:19 AM
SMU = SOURCE Measure Unit. You are not measuring the input voltage of the device (ie the power you are sourcing into the device); you are measuring the output of the regulator. Therefore, a DMM is the device you should be using.
09-24-2020 08:09 AM
We can set a SMU to Source Current mode with the below settings and measure the voltage. Can you explain in more detail on why we shouldn't use SMU to measure voltage.
O\P current = 0A.
Voltage Range and Compliance = Voltage to be measured + 1V
09-24-2020 10:42 AM
@Incognito_Guy wrote:
Can you explain in more detail on why we shouldn't use SMU to measure voltage?
An SMU is a basically a power supply with very accurate measurements on its output. It is not designed to measure the output of other devices. You should be using a DMM.
09-24-2020 02:46 PM
Sounds like a perfect application for an SMU to me. Not only is it accurate enough to measure the output voltage of "5V typical," it can also provide the 100mA load to check the load regulation. Remote sense should be used for the load regulation test to ensure you're not just measuring the resistance of the connecting leads.
09-27-2020 11:32 AM
You can go with either DMM or SMU. There are advantages and disadvantages to both approaches.
DMM
SMU
From my experience with both silicon validation and production testing,