UCC2803 Testing of Threshold values

All the values on the IC are referenced to its GND pin.

If this is not what you ask, please describe your questions more in detail.

All the values, I mean the voltage values and if they are not particularly conditioned.

Thank you, Hong Huang.

What I was looking for, was how do you actually do the threshold test?  In most IC's thresholds are done by monitoring the output, compared to some other input or output of the IC.  I was wondering how you read the threshold levels?  Do you just monitor the input VCC and the output, or do you monitor the COMP while adjusting the VCC and watch the output level to determine the trip-point?

Or do you change/monitor the Reference input and monitor the output to obtain the threshold?

I hope this is a little better to understand

Tom Fivehouse

During the test, VCC is set up in its specified range then we do the test with its MIN and MAX. After VCC is set up in its operational range, the OUT pin status is checked with COMP, and CS. REF is tested to confirm its value is in the specified range of the datasheet.

Sorry, I feel I do still not fully understand your concerns. Can you describe what exactly the issues are in your applications, directly and straight forward? I would think this way would help to avoid misunderstanding. 

What I needed to clarify is where is the threshold read? 

The typical threshold ON/OFF is specified as 4.1V/3.6V respectively.  Are these values read at the REF pin (pin-8?) 

What are you looking at on COMP & CS?  Are you verifying that the COMP freq is turned off and there is no output?

I am sorry for all these questions, but I am not used to testing these parameters on this type of device.

Are you referring VCC or OUT? You mentioned both in your previous messages.

On the VCC, the table specifies the below to make the IC normal work with VCC distributions. Are you referring this?

On the REF, the datasheet specifies:

Since OUT mentioned in your previous message, if it is what you need to know, OUT  is related to CS and COMP.

Please let me know which above is what you want to know. If none of them, please indicate which page and which paragraph you would like to knwo the test set up. Where is 4.1V/3.6V found in the datasheet?

I think you are referring the below. If so, the 3.6V and 4.1V are typical VCC UVLO on and off thresholds.

VCC has MIN and MAX as well. Our test setup is to check OUT of a device under test to make sure it is in swtiching operation with VCC at MIN and at MAX. Its Typical value is usually an averaged value from the test results.

Hope this answered your question. Otherwise, we will make further discussion.

To make it further clear, we do the test to make sure OUT switching with VCC in between MIN and MAX of its ON threshold. We also do the test to make sure OUT not switching with VCC in between MIN and MAX of its OFF threshold.

Thank you, Hong Huang.

The last two posts did answer my questions.  The tables are now clear to me.  At first they were a little confusing, now I understand.

I appreciate your patience and help with this posting.  I see now where we need to test the devices.

Again, Thank you for all your help!

Tom Fivehouse