BQ24074: BAT pin(2,3) = 1.64V in pre-charge mode.

Hi,

When my BQ24074 working on pre-charge mode, BAT pin(2,3) voltage is only 1.64V. I tried to remove the battery, the floating BAT pin(2,3) voltage is still 1.64V. Is this normal? Attached is my circuit diagram, please help to check if there is any problem with my circuit.

Thank you.

TK

Star Xu：

您好，正在询问更了解这款芯片的TI工程师，稍后回复。

,

Star Xu：

您好 ，请参考下面内容

I see that you're seeing the attempting to put the ILIM to 1.86 A (although an ILIM resistor of 820 sets it to 1.96 A). This is outside of the device's operation of 1.5 A max ILIM.  For reference, a resistor of about 1100 Ohm sets it to 1.46 A. 

As far as the behavior you are seeing, yes; this should be normal. What happens is the TS becomes floating and so the device is no longer charging. As we do not source or pull current from the BAT pin, the capacitor will discharge naturally (although very slowly) which is why you see 1.64 V.