Current Sense Resistor

I am not very good at deciphering the specs on the Cleverscope so I have a couple of (probably stupid) questions.

1. What is the minimum voltage that can be measured?
2. Using a current sense resistor what is the minimum amperage that can be measured?

Thanks,
Eric

I am not very good at deciphering the specs on the Cleverscope so I have a couple of (probably stupid) questions. 1. What is the minimum voltage that can be measured? 2. Using a current sense resistor what is the minimum amperage that can be measured? Thanks, Eric

Hello Eric, 1.The minimum DC voltage without averaging, and accuracy of about 10%, is 20mV. With averaging you will improve that to about 2mV, but accuracy is still no better than 1% of the full scale range. You will get much better relative accuracy than absolute accuracy. If you are looking in the frequency domain, you can resolve down to about 30uV , and 3 uV with averaging, for signals away from DC.

2. It depends on what size current sense resistor you use. For example with a 1 ohm resistor, this would be 20 mA with no averaging, or 2 mA with averaging. If you are trying to resolve smaller currents, then you can use a larger resistor - for example 10 ohms will give you 2 mA without averaging, or 200 uA with averaging. You will be able to resolve much smaller currents, at a level relative to some baseline.

Hello Eric, 1.The minimum DC voltage without averaging, and accuracy of about 10%, is 20mV. With averaging you will improve that to about 2mV, but accuracy is still no better than 1% of the full scale range. You will get much better relative accuracy than absolute accuracy. If you are looking in the frequency domain, you can resolve down to about 30uV , and 3 uV with averaging, for signals away from DC. 2. It depends on what size current sense resistor you use. For example with a 1 ohm resistor, this would be 20 mA with no averaging, or 2 mA with averaging. If you are trying to resolve smaller currents, then you can use a larger resistor - for example 10 ohms will give you 2 mA without averaging, or 200 uA with averaging. You will be able to resolve much smaller currents, at a level relative to some baseline.