I am trying to evaluate the BQ34Z950. Following suggestions I read on another post I am using the BQ20Z95 EVM I have made the following changes to the board
To bench test, acquire a bq20z65 or bq20z95 EVM and make the following modification:
1) Short D2, the diode between pin16 and TP3.
2) Takes off D3 and Q1 that connect to FUSE pin
I can connect to the board using HDQ or using the SMB connections.
I have the link to the updated version of the PC software, the data is being read back correctly but I am having problems with writing data. This is what I get on my screen:
I can't charge or discharge the battery pack as the output FETs appear to be turned off, if I run the calibration tests then they are turned on for the tests, so I have no reason to believe that they are not working, at least the output FET for sure on the current test. The pack I am using is a 3 cell pack. I have managed to change the mode of the pack to reflect that there are 3 cells in it:
If I try to change other parameters such as Term Voltage in Gas Guaging or design voltage in SBS Configuration, if I click on 'Write Class', Write SubClass', or 'Write All' it appears to have written correctly with no errors but then resets to the original value when read back again.
I have tried with just running off the cells, just off the power supply without the cells present, and with both on. I just can't this to enable charging or device operation in a sensible way.
I have set the bqCHEM to the A123 cells which I am using and have run through the calibrations, but there is still no output from the battery pack.
I'm basically out of ideas, so any pointers would be much appreciated. You can get me on here or directly by email to mhill at race-technology dot com.
Thanks very much,
Martin