BQ25601: BQ25601 work abnormal

Hi Star,

Please make the following changes to your schematic:

1) Connect a 1 µF capacitor from VBUS to GND.

2) Connect a 4.7 µF capacitor from REGN to GND.

I also have a few questions to debug this:

1) What is the current capability of 5V0_IN in your schematic?

2) What is the current capability of the DC power supply that turned on the load board successfully? Is this DC power supply the same as 5V0_IN in your schematic?

3) How much current does the load board draw when it is turned on?

4) Can you please read the registers and send a register dump after the VSYS dip shown in your waveform?

5) Do you have a BQ25601 EVM that you can test this on? If so, does the EVM also have the same issue?

Best regards,

Angelo

Hi Angelo

Thanks for your reply.

1. The current of 5V0_IN is just milliamps when the load board is not turned on.

2. The current capacity of dc power supply of load board (without BQ25601) is 700ma, and the voltage input from 4.6 to 5V is ok

3. When the load board is power on, the current is about 300ma

4. When use BQ25601, the load board  can not be power on and the register cannot be read

5. The customer purchased BQ25601 EVM and will take a few days to arrive.

Thanks

Star

Hi Star,

Okay, please let me know the results after you're able to test this with an EVM.

Regarding 1) and 2), What is the maximum amount of current that 5V0_IN and the DC power supply can provide? In other words, what is the current limit?

Regarding 4), why can't you read the registers when the load board is off? As long as the VBUS = 5 V input is connected to the BQ25601, then you should still be able to read the registers even if VSYS is floating.

Best regards,

Angelo