Other Parts Discussed in Thread: BQ24650
Dear Expert, I measure my charging current. It is smaller than my setting. Such as if I set the charging current equal to 900mA, I measure the charging current is about 850mA on TI EVB board. But I measure my PCB board, It is about 780mA(average current on oscilloscope, it's maximum current is about 900mA). What's the root cause? My sense resistor is10 mΩ, the same with TI EVB. Whether I should increase the value of sense resistor? Another issue is the heat of bq24610. When the battery is charging, the bq24610 will heat, but charging can be proceed. Below is my PCB layout, the red block is bq24610, it is mounted on PCB's bottom layer. My PCB is 4-layer. the bq24610's thermal PAD is assigned to AGND on the PCB's second layer(Blue region). The AGND is connected to the PGND via the 0805 0Ω resistor(yellow block). Whether my AGND's area is too smaller to spread out the bq24610's heat? The Taiwan FAE tell me, the heat just will happen on external MOSFET, the bq24610 just is a switching controller and will not be heated. Is this right? Thanks.
