LTC4007 datasheet provides typical application circuit for a 3-cell, 4A LiPo battery charger. I have read the datasheet and designed the following circuit. We have fabricated the board, and are now testing it. However, the circuit does not charge the battery. The circuit turns on FET Q4, but holds Q3 and Q5 OFF, therefore nothing is switching. Why is the circuit remaining off? The input voltage is 11.8V and the battery voltage is 11V. With those voltages, the chip should detect the lower battery voltage and start charging. I do not see any reason why the chip would be in a disabled state. The NTC detect should be disabled due to the 309kohm resistor. I disabled the input supply current limited via connecting CLP and CLN (as recommended in datasheet). I set the programming resistor and sense resistors per datasheet as well.
If anyone knows why this circuit isn't charging the battery, please let me know!! Thank you!
