Tool/software:
Hi, please ignore my other thread regarding brownouts for now, I've still not been able to capture the issue in the lab again. It may have been fixed......
We are running into a couple of odd other issues with the BQ256232E chip. During testing we are doing some simple stress testing.
When I apply a 3A sudden sustained load without a battery inserted and the BQ is at its POR default state, the vSys collapses and fails to recover.
The blue line is our 12V psu supply.
However after narrowing down which registers made it "work"
I found when applying these two values in our startup code on our project:
writeRegister8(BQ25622Register::ChargerControl1, 0b1'0'1'0'0'0'01);
writeRegister8(BQ25622Register::ChargerControl2, 0b0'1'10'01'0'1);
Charger Control 1 should be the POR default state but for some reason this is still required to be applied to make the second Charger Control 2 register entry to take effect.
The key change in the second register entry is setting the SET_CONV_STRN value to ether weak or normal "fixes" the complete crash out.
But we still get a short square dip with a sudden sustained 3A load without a battery inserted..
Where using a 2.2uH inductor and the RC filter has been hacked onto the board.
Layout might not be 100% ideal and doesn't match the reference in the datasheet, but vsys has a low impedance path to the inductor as does the switch.
Is this normal expected behaviour ?
Is my PCB layout a mess?
Or am I pushing the chip too hard?
Other thing to note, the chip doesnt like running at 3A for very long, not that I've seen increased instability, more that it can reach 100C.
The project this is sitting in wont ever reach sustained current draws like that. But it is well within the spec of the circuit. So its making me wonder why its getting so hot too.
I should note, the project doesnt appear to reset when I get this square voltage dip. Its short enough that things carry on, but its not ideal.
If anyone can help clear that up for me... Its the final issue I'm facing with this chip.
