BQ76PL455A-Q1: RESETTING THE IC

Hello User,

You can refer to 7.4.1 SHUTDOWN for more details.

Thanks!

hello, the section suggests to disable wakeup but actually I have internally routed it to v5va0. Is there any other hardware option for reset?

I have checked with the software options through uart but I do need a hardware option for a reset signal.

Hello user,

" disable wakeup but actually I have internally routed it to v5va0."

Can you explain little bit more detail about internally routed to v5va0?

Roger

I connected wakeup pin with v5va0 while designing my PCB for BMS. Since the NPN regulator generates a 5V logic for VDIG and VP which then goes to IC for the generation of a 5V logic for V5VA0. And in order to start the IC we need to give Wakeup pin a high logic level of more than 2.3V. So, I routed it with V5VA0

Raj,

HQ is in holiday.

Roger would get back you after holiday.

Here is my comments. wakeup pin is normally in Low level.

The WAKEUP pin can bring the part from the SHUTDOWN state to the IDLE state. It can do this in any stack
position. However, typically only the base device uses it when driven from a microcontroller. The pin is level
sensitive and is normally at a low (logic-zero) level. When the part is in SHUTDOWN and the WAKEUP pin
becomes high, the part will transition from SHUTDOWN to IDLE. After applying the high signal, the WAKEUP pin
must de-assert and then return to the low state to allow the part to enter SHUTDOWN again. Upon changing
state, the bq76PL455A-Q1 will briefly transmit a differential wakeup tone on its COMMH+ and COMMH– pins to
the next higher bq76PL455A-Q1, where that device's COMML+ and COMML– pins receives it.

Raj,

Wake up shouldn't be connected to external circuit. It can't manage any load.

I like to see a your schematic.

roger

7802.Passive_BMS_E1.pdf

Hi Raj,

Your schematic is very close to our evm which is good idea.

I reviewed the schematic and I have following suggestions/concerns.

1. D32 diode. Please double check the Vr spec. I could be wrong but you have 16V TVS diode. Please confirm.

2. D33A ( as example), please use lowest leakage diode. Spec shows 3uA leakage and that will lead to measurement error.

V error=1K*3uA

3. Recommendation for OUT12 cap is 390pF for best accuracy. I think datasheet has register settings for 390pF.

4. Vref cap values is important too.

5.V5VAO cap value as well.

6. V5VAO is not meant for external circuit. you have 100K so it's not lot of load but something to watch out.

7. R85 should be min 100ohm for hot-plug. if you don't have any issue with hot-plug then it's okay.

If you are okay then I suggest you to copy cap values from our evm.

And also check this apps note. You will find useful information.

Roger