I have implemented the bq24100 as attached and can not get it to charge. Vin is 5.25V, Vbat is 2.67V (18650 cekk), TS is 1.58V, CE is low. PG led lights, but Stat1 and Stat2 are off. Same input and battery on eval module charges just fine. Any suggestions as to what I should check next?
Thanks,
Thank you for your reply - I am making progress, but still having issues.
I purchased another bq24100 evm and populated it with the components that I calculated from the datasheet. The first thing that I found was that the circuit began oscillating as soon as I replace the RT1/RT2 taken from p27 of the Nov 15 datasheet (RT1=9k31/RT2=442k w/10k thermistor) with those on the eval board (RT1=4k99, RT2=10k) and disconnected the thermistor. Even a 10k resistor substituted for the thermistor held the circuit off with the original values.
With the new RT values, the circuit would start to charge, but cut out after a few seconds. I found this was related to the long wires I had between the circuit board and the battery holder. Shortening the wires got the circuit charging at 1.5A, but again it only seems to charge for a minute or so before it cuts out leaving only the PG LED on, Vin = 5.25V, Vo sits at 3.76V with no oscillation, Vb is 3.76V and /PG is low.
The first photo shows the circuit just after power is applied and it is charging at 1.5A, Top trace is Vin, next down is Vo, then Vbat and /PG at 1ms/div
I get 1.08MHz as the frequency of oscillation.
Below is the same circuit with the timebase at 100ms/div showing no dropouts or issues with any of the signals.
I tried to copy the layout from the eval board as closely as I could, but there is one area where I am going to try adding some additional grounding to see if it is cutting out from noise on the PG pins.
Any other suggestions you might have would be appreciated.
Bob
