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    Ground loop of Agilent 33250A

    Thank you for your reply. For answer 1, may I say the current is determined by Vgnd/Rwire? If it could be, then how could the 1Mohm resistor and the capacitor reduce the effect of Ignd? or more clearly, reduce Ignd? For answer 2, no ground current doesn't mean no current. the Zshield still...
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    Ground loop of Agilent 33250A

    Hi all, I have some questions about the manual of Agilent 33250A, " Ground Loops Except for its remote interface connectors and trigger connector, the 33250A is isolated from chassis (earth) ground. This isolation helps to eliminate ground loops in your system and also allows you to reference...
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    Question about grounding

    For the attached circuit,the two resistors have same resistance value. I connect the +/- polar of a battery to the A, B point correspondingly. Then I measure the voltage of A to ground and B to ground, I find that the potential of A and B will always be 2+ half the battery voltage and 2- half...
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    Question about grounding

    Hi, I have a question about some materials I've read in terms of grounding. Below is the material. " III An Illustration of a Typical Power Supply Grounding Error As previously pointed out, the ground symbol, in many cases, has been taken as a generic symbol in electronic circuit diagrams to...
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    Stable floating power supply

    Hi, I have a MEMS device which is simply a actuator connected to a displacement sensor. I apply a voltage to the actuator to make it move forward, the load sensor is connected to a conditioning circuit, from the output voltage of the conditioning circuit, I could tell the displacement. Now I...
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    What kind of lead should I use?

    Hi, I have a PGA chip(attachements). I wonder what kind of leads can I used to connect the pins in the PGA chip, just like shown in attachments?
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    Theory of operation of MS3110 high resolution capacitive sensor

    Sorry, I know repeatly open the same topic is boring. The reason I want to know how does MS3110 work is because my advisor asks me to do this. He used to use the MS3110 when he was a student, but with a different transfer function. He said the circuit now shows no difference with the one he...
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    Theory of operation of MS3110 high resolution capacitive sensor

    Now I have a square wave which has a high level of 2.25*C1/Cf+2.25 and low level of 2.25*C2/Cf +2.25, and after a low pass filter, this signal becomes a DC voltage with a value of 2.25*1.14*(C1-C2)/Cf+2.25, I want to know how could this happen?
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    Theory of operation of MS3110 high resolution capacitive sensor

    Hi, could anyone tell me how a low pass filter could transfer a square wave(supposing alternating between A and B volt) to a DC voltage? Thanks in advance.
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    Theory of operation of MS3110 high resolution capacitive sensor

    Hi, I am working on MS3110, a high resolution capacitive readout sensor. Here is the simplified circuit for MS3110. The two switches are 180 degree out of phase, ie. S1 connect to 2.25V, S2 connect to ground. The switching frequency is f. After discussing with others, we think theory of...
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    Theory of operation of MS3110 high resolution capacitive sensor

    Hi Laplace, Please check my latest explanation. I think perhaps we can derive the transfer function without knowing the timing information. When S1 is connected to 2.25V, S2 connected to ground, C1 has 0 potential difference, according to Q=CV, there should be no charge on the C1 parallel...
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    Theory of operation of MS3110 high resolution capacitive sensor

    I think now I understand the operation of this circuit relies on timing control.Maybe it's not practical for me to derive the transfer function. I still want to know do you think my analysis shown above is right? especially the capacitive switch circuit part? In this circuit, can the capacitor...
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    Theory of operation of MS3110 high resolution capacitive sensor

    I will use MS3110 to measure tiny capacitance difference in a MEMS device. For better use it, I try to understand the theory of operation. Could anyone tell me how to understand the MS3110 IC's circuit? Transfer function I have some idea after studying and discussing with others. 1...
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    Theory of operation of MS3110 high resolution capacitive sensor

    Hi Laplace, I learnt some basic switch circuit and found that a capacitor（C） in a switch circuit is equal to a resistor having a resistance of R=T/C, T is the switching period. So when the upper source is 2.25V, the lower source is 0V, we have a simplified circuit like the following: Current...
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    What does the symbol imply?

    Hi, I am working on the transfer function of MS3110, I want to know how the transfer function is derived. I have post another thread on this https://www.electronicspoint.com/threads/ms3110-high-resolution-capacitive-readout-circuit.270929/ , would you please give me some instruction if you have...
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    Theory of operation of MS3110 high resolution capacitive sensor

    Yeah, you are right. It is a switched circuit and from other material I know that the frequency of open and close the switch is 100KHz. I think the center of the capacitor bridge is kept at 2.25V and and the capacitors on the two sides of center are alternatively charge and discharge, just like...
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    Theory of operation of MS3110 high resolution capacitive sensor

    According to what you said, the problem can be simplified as the following, Here we make several simplifications 1. V+ = V- = 2.25V which is also the node1's potential since no resistor between node1 and noninverting input. 2. CS1N || CS1 = CS1N + CS1 = Cx ; CS2N // CS2 =CS2N +CS2 = Cy 3. The...
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    What does the symbol imply?

    Thanks a lot!
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    What does the symbol imply?

    Yeah, it seems you are right. Then does this part in the circuit provides a square wave between 2.25V and 0V? And this part provides a out of phase square wave also between 2.25V and 0V?
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    What does the symbol imply?

    Actually this is the from the datasheet of MS3110, a sensor used to measure tiny capacitance change.
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