Hello everyone,
I am testing the BQ24083EVM and during my testing I came across a problem I can not quite solve. I am testing for the Vil and Vih of the CE and VBSEL pins and according to the datasheet I am suppose to get a Vih of 1.4V or higher and a Vil of 0 to 0.4V. I am using a step search using a source meter and record the Vih at 0.92V and Vil at 0.91V. I am hoping that I can get some insight on a possible alternative method to test this or maybe there was suppose to be a test condition that was not recorded in the datasheet. Thank you for your time.
http://www.ti.com/litv/pdf/slus848a (BQ24083 datasheet)
http://www.ti.com/litv/pdf/sluu315 (BQ24083EVM user guide)
Hi David,
Yes, the VIL and VIH should work as in the datasheet spec. In the EVM, we use jumper JMP5 and JMP4, with 20KOhms pulled to Vin for both CE AND VBSEL . Use a pull up resistor for both of these pins than vary the pull up voltage. This should be a good test. Of course you to power up the IC for proper operation.
-Tahar
Thank you for your input. I just wanted to confirm my setup with you on this. I have two sourcemeters, one to power the evaluation board and the other to test the Vil Vih. I am powering the board at 5V and the other source is connected to either JMP4 that is connected to the CE pin and I have placed a 20K resistor in series with the JMP4 and source. Then I still produce the wrong Vil Vih values.
David,
Yes your testing method is right. What do you call wrong values? The datasheet guaranties low for any values below 0.4V and high for any values above 1.4V. Between 0.4V and 1.4V we do not guaranty it to be low or high.
Ah, we thought that our Vih value had to be above 1.4V and Vil value below 0.4V. This was very helpful and we thank you for your time. One other quick question, is there upper ESD diodes in this charger? We tested and were able to measure the lower ESD diode in each of the pins, but not the upper.
All pins of the IC meet the specified ESD performance.