BQ27425-G2A: BQ27425-G2A

Hi

Before you attempt to use this gauge, pls verify if this is the right gauge for your cell. We have had customers go far in their design process only to realize that this gauge would not work for their battery type.

Our online tool gpcchem will allow you determine if this gauge works for your cell type. pls run the test listed in the instructions and submit to the too before even beginning to evaluate the device.

As for the internal sense resistor values, are you measuring on an evm or your board. You know that the equivalent resistance at those nodes will depend on the components of your circuit. Why are you measuring it in the first place? Are you having current being reported wrongly?

thanks

Onyx

200kOhm between SRX and VCC is way excessive. This should be around 10mOhm. It's implemented in a metal layer on the chip so if you measure 200kOhm, it was probably damaged (excessive current? - it can't handle more than 2A rms long time and 3.5A 250ms peak pulse with 1% device utilization ).

Hello Ido,

What do you mean the gauge is damaged?

I looked at the schematic and you should be able to handle 5 volts on LiPo_Power.

Hello Ido,

Make sure you are not applying more than 3 amps of continuous DC current through the chip. That will definitely damage the part. This part is meant to only support low currents of 3 amps or less.

Hello Ido,

I do not think so, I recommend you scope the SRX and BAT pin on insertion event to look for high transient voltages or currents.

Hi Kang

ok

Hello Ido,

I have never seen this type of scope before, however, it looks like there are higher transients towards 7 volts. Can you measure a few more? That way we get a better understanding of the transients. I recommend following the abs max specs on the datasheet.

Hello Ido,

ESD protection is not spec'd when the device is powered. That will be based on IEC standards.

The HBM ESD is only when the IC is not powered.

The gauge cannot handle 12 amps for any length of time. Please follow the datasheet.

It may be due to the capacitors on REGIN and VCC.

If you connect a charged battery with low internal resistance then the inrush current into these capacitors can be fairly high. Disconnect both capacitors and try again (experiment to isolate the cause).

Hello Ido,

We don't. This still looks to be a board problem. I would recommend doing the same test on the EVM.

Hello Ido,

Yes, it is because your system is pulling the in-rush current. It is your system capacitance that guides how much in-rush. That in-rush current damages the gauge as it exceeds the abs max.

Hello Ido,

That doesn't make any sense. Please debug your board level setup. Please try this with an EVM instead. You should not see any in-rush current if your system load is not connected.

Hello Ido,

I've answered these questions multiple times and in different ways. Please go by the operating conditions of the datasheet for these.

Hello Ido,

I think I understand your question now.

I do not recommend this because it is tough for us to put a utilization number for it. It is the BGA balls that are the limit and these specs are from our package team.

I do not recommend going above 3.5 amps for this device at any instant. For a better part, please look at the bq27426.