Hi, I'm Tomo from Agilent Technologies.
Today, I'd like to demonstrate how to use an SMU, source measure unit, as an ammeter.
This is an equivalent circuit to use in this demonstration.
This circuit consists of a DC voltage source and a resistance.
An ammeter is connected in series.
If the ammeter is ideal,
you can connect the ammeter either positive or negative terminal of the voltage source.
When we use an SMU as an ammeter,
we need to set output conditions correctly as an ideal ammeter.
An ideal ammeter must have following features.
An ammeter must be a floating ground because it can be connected in series anywhere.
An ideal ammeter has zero resistance like a short circuit.
So the terminal voltage must be 0 V.
SMU has a precision source function.
So it can behave like an ideal ammeter.
This is an equivalent circuit of SMU.
SMU consists of 4 major function,
current source, voltage source, voltmeter, and ammeter.
And it can switch between grounded and floating.
SMU has two low terminal states,
one is a grounded state, the other is a floating state.
The low terminal state is set to floating state.
SMU has two source modes,
one is a voltage source, the other is a current source.
The source mode is set to voltage source.
The voltage source is set to 0 V.
This electric circuit is equivalent to an ideal ammeter.
In addition, you have to care about current limit to use a SMU as an ammeter.
A current limit is a function to protect a test device against over current.
In this case, you have to set larger value than expected measured value.
I'll show you how to set output conditions with the front panel.
I have to set the low terminal state to floating first.
This symbol indicates floating state.
And then, I set the source mode to voltage mode.
Voltage level to 0 V.
Current limit to 10 mA.
In this time, I'm going to turn on zoom fucntion so that we can easily see measured value.
Let's start measuring.
Firstly, I'm going to connect the SMU to the negative terminal of the DC voltage source.
The measured current is about 3.12 mA.
Secondly, I'm going to connect the SMU to the positive terminal of the DC voltage source.
The measured current is about 3.12 mA.
This result is equal to the previous one.
I've demonstrated how to use a SMU as an ammeter.
SMU has a precision source function.
Besides, it can be used as floating ground.
So you can use an SMU like an ideal ammeter.
If you like to have more information, you can visit our website.
Thank you.