BQ25618: I2C register reset condition

Toshiro Imi

Part Number: BQ25618

Tool/software:

Hello,

Our customer has a question what event the I2C data make reset.
As far as looking at the datasheet, I2C data is reset by Watch dog timer expired, REG_RST=1, VBUS < VBUS_UVLOZ & VBAT < VBAT_UVLOZ.

Is my understanding correct ?

Please let us know if there are other conditions.

Best regards,

4 months ago

0 Michael Emanuel35 4 months ago

TI__Mastermind 40275 points

Hello,

Also as shown in Section 7.3.7.3.

Regards,

Mike Emanuel

0 Toshiro Imi 4 months ago in reply to Michael Emanuel35

TI__Expert 7170 points

Hello,

I checked session 7.3.7.3 but that describes BATFET system reset. Is BQ25618 I2C registers reset by /QON=Low or BATFET system reset ?

regards,

0 Michael Emanuel35 4 months ago in reply to Toshiro Imi

TI__Mastermind 40275 points

Hello,

It says in that section, "After the reset is complete, the device is in the POR state, and all registers are in POR default settings."

Regards,

Mike Emanuel

0 Toshiro Imi 4 months ago in reply to Michael Emanuel35

TI__Expert 7170 points

As I tested in lab but registers were not reset.
I think system connected to VSYS is reset but BQ25618 I2C registers are not reset.

(datasheet "7.3.7.3. BATFET Full System Reset" description)
By changing the state of BATFET from on to off, systems connected to SYS can be effectively forced to have a power-on-reset. After the reset is complete, the device is in the POR state, and all registers are in POR default settings.

My test procedure is as shown below.
1. plug in VBUS=5V, VBAT=3.7V. measured VSYS=3.8V
2. change ICHG current limit to 1.0A, watchdog timer=disabled.
3. VBUS pug out, VBUS open. measured VSYS=3.7V
4. BATFET_DIS=1, BATFET_RST_EN=1 (default).
5. after checked VSYS shut down, read all registers, but are not turn to reset condition.

regards,

0 Michael Emanuel35 4 months ago in reply to Toshiro Imi

TI__Mastermind 40275 points

Hello,

Can you retry step 4 but without BATFET_DIS = 1?

Regards,

Mike Emanuel

0 Toshiro Imi 4 months ago in reply to Michael Emanuel35

TI__Expert 7170 points

Do you mean BATFET_DIS=0 and test again ? if so, that is same as "3" and registers are not reset.

what we need to know is I2C register reset condition.

0 Michael Emanuel35 4 months ago in reply to Toshiro Imi

TI__Mastermind 40275 points

Hello,

We are observing Good Friday and will get back to you by next Tuesday.

Regards,

Mike Emanuel

0 Michael Emanuel35 4 months ago in reply to Michael Emanuel35

TI__Mastermind 40275 points

Hello,

These two line items are not the same. Do not disable the BATFET before performing a system reset.

Toshiro Imi said:
3. VBUS pug out, VBUS open. measured VSYS=3.7V

Toshiro Imi said:
Do you mean BATFET_DIS=0 and test again ? if so, that is same as "3" and registers are not reset.

Regards,

Mike Emanuel

Power management

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BQ25618: I2C register reset condition