Tool/software:
Hi,
My design with the BQ77915 is the following. I am not using the CHG and DSG option, just the balancing;
I am observing strange behaviour on CHG pin (DSG is also always low..).
I am not using temp sensor, so it should not be a temperature error.
The only errors left that have both CHG and DSG OFF are:
- OW: no, I checked voltage difference
- OCC: also no, I have (VSRP – VSRN) = 40mV
-OCD1, OCD2, SCD: I am in charge so it should not be this.
What am I missing ?
Regards
Hi Thomas,
y
This node seems not quite right. PRES should be driven high for normal mode, its being shorted to ground it looks like.
Regards,
Max Verboncoeur
Hi,
Yes sorry, it is an old version, in the one I am testing, PRES is correctly tied:
In fact, I see this behaviour when device is supplied by battery or charger (with a charge current).
When charging, chip seems to equilibrate, so I am fine with this behaviour.
But when only battery is plugged, I want to minimize consumption, and I assume this oscillation consumes current (1-2mA), far from the 8uA of normal mode.
I was wondering how the chip could detect the presence/absence of sector without falling under the VOCC range:
i.e what happens when VOCC < 5mV ?
Hello,
How are you measuring the current consumption of the device? The current should be measured at the VDD pin. Measuring this voltage across this resistor:
Best regards,
Thomas Rainey
