interface labview with the test board to identify opamp pins automatically

[pratheek]

is it possible to interface LABVIEW to a test board in such a way that the input, output pins of an op amp (8, 10, 14, 16 pin opamps) are identified automatically when DUT is placed in the socket

[Ranjeet_Singh]

For that only way I can think is you will know the input values and if you receive proper output then you can say is input output is OK.

[pratheek]

I am sorry. I didnt get you. Actually my project is to test the funcional and test parameters of a wide range of opamps. For this I need to design a circuit in such a way that, when an op amp is placed in the socket it should identify all the pins of opamp automatically and test the parameters when interfaced with LABVIEW. So I would like to know how can i do it using labview. I just know only the basics of labview 😞 

[pjr1121]

The first thing you need to do is identify the process of evaluating the opamps without labVIEW.  What voltage will you apply to the various pins and in which sequence?  Are these all 8-pin chips or does the pin number allocation need to be variable?  First develop a full test sequence that you would use manually, then focus on how to do it through LabVIEW.  After plugging in a random IC, which values do you apply to the various pins and what is the desired output?  

I'm assuming you would be using a DAQ of somesort and a series of switches to control which DAQ i/o pins are connected to each pin of the chip.

[pratheek]

Thanks alot. pin numbers are variable. I need to test the functional and test parameters for 8, 10, 14, 16 pin opamps. The desired out put for my project is to check the functionality of the opamps

[pjr1121]

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@pratheek wrote:

Thanks alot. pin numbers are variable. I need to test the functional and test parameters for 8, 10, 14, 16 pin opamps.

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The first thing you need to do is ensure that +VCC, -VCC, and GND are always connected to the correct pins.  I think the best way to do this is have preset wire options that you manually select with some switches (reduces the complexity of the LabVIEW controlled wire switching).

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@pratheek wrote:

The desired out put for my project is to check the functionality of the opamps

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I understand the end goal, but what you need for first specity is the test sequence.

1. Identify In/Out pins & number of op-amps.  What is the sequence for this??? What voltages do you apply to the various pins and what is your desired outcome???  How do you identify each pin as in/out and whether they are for OpAmp1, OpAmp2, etc.  Since this sequence will inevitabely apply voltage to the output pins, make sure your test sequence doesn't damage the chips.

2. After identfying each op-amp, what is the test sequence for evaluate its "functionality"??  Do you wish to evaluate the gain for various resistor combinations in an external circuit????

3. Now with your test sequences outlined, you can finally begin on getting LabVIEW to implement these functions.  I'd use the DAQ digital outputs to a decoder (3-to-8 or 4-to-16).  Use the outputs of the decoder to control switches (these switches control the connections between a second DAQ and the test pins).  A third DAQ may even be necessary to control the selection of various test resistors.  Keep in mind that each of these switches will add resistance to the path so your evaluation must be made measuring the voltages at the op-amp pins (not using the sourced voltage values).  Planning the full measurement sequence and requirements before you start will not only help guide your program's development but it will tell you which DAQs are useful and how many you will need.

This is quite an undertaking and we can't really provide any help on the LabVIEW end until you have a full write up of what you want to happen and how (step-by-step details).  Once you have that, start thinking about the sequence of events your code will have to follow to make it happen, then come back for guidance/help.

[Dennis_Knutson]

I agree with the others that you are a long ways from any LabVIEW code. Have you even thought about how you are going to prevent the ic from being inserted backwards? For the insertion, you might want to consider a camera system that looks at the ic, sees the size and orientation, and reads the part number.

[pjr1121]

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@Dennis_Knutson wrote:
I agree with the others that you are a long ways from any LabVIEW code. Have you even thought about how you are going to prevent the ic from being inserted backwards? For the insertion, you might want to consider a camera system that looks at the ic, sees the size and orientation, and reads the part number.

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I would agree with some method of ensuring correct mounting if this system is going to be widely used.  If it is for you alone, you can probably get away with just being very careful.

[camerond]

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@Dennis_Knutson wrote:
I agree with the others that you are a long ways from any LabVIEW code. Have you even thought about how you are going to prevent the ic from being inserted backwards? For the insertion, you might want to consider a camera system that looks at the ic, sees the size and orientation, and reads the part number.

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Good point! pratheek, have you ever inserted an op amp backwards in its socket and powered up? It can have a YouTube-worthy result!

 (sorry pjr, misread the OP at first)

Cameron

[pjr1121]

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@camerond wrote:

 have you ever inserted an op amp backwards in its socket and powered up? It can have a YouTube-worthy result!

 (sorry pjr, missed the OP at first)

Cameron

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I've blown up many IC, transistors, capacitors and resistors over the years.  Always seems to be accompanied by a destinct burning smell and a lot of cursing.