BQ24075-Q1: CHG of BQ24075 always low

Part Number:BQ24075-Q1

Hi,sir,

I used BQ24075-Q1 for battery charge and the schematics is as following:

If the battery is absent, CHG pin still goes low. The charging function goes well but CHG pin is always low even it's completed. I reviewed the datasheet again and added 100K pull up resistor of CHG pin, but there is no change and CHG pin is low too. 

Wait for your reply. Thank you!