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Vijay
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DA14683 Power Supply

Hi,

We have built boards based on DA14683 chip. The boards are yet to be programmed.

I see that there is no voltage seen on "VDD1V8P" rail on some boards, on a very few boards it is about 2.6V and on most of the boards, it is 1.8V. Rest of the supplies V33, VDD1V8, V12, V14 are measuring accurate on all boards. We have 2 sensor chips and 1 RTC chip on the VDD1V8P rail.

The board hardly draws any current. Can I know what is happening to this rail? How to fix it?

Regards,

Vijay

 

Device: 
Device Number: 
DA14683
MHv_Dialog
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Hi Vijay,

Hi Vijay,

I have asked our HW support team to look into this. Nothing obvious springs to mind...

/MHv 

Vijay
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Last seen: 1 month 13 hours ago
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Hi,

Hi,

We programmed the good boards where VDD1V8P measures 1.8V. After we program the boards we see 2.6V on the same bus irrespective whether the battery is connected to the board or not. All other supplies look OK. Battery seems to charge OK. We use DA1468x_DA15xxx_SDK_1.0.14.1081

We are using the DA14681 watch development kit to load our code. 

Look forward to receiving a solution.

 

Vijay

 

MHv_Dialog
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Hi Vijay,

Hi Vijay,

I received the following from our internal support team:

"

since the V18P rail is also used for GPIO supply (when these are set to the 1.8 V rail), the 2.8 V level on the V18P rail is most probably caused by an external chip (SPI/I2C/UART) that operates on 3.3 V. The 683 GPIO will face 3.3 V levels, and via the ESD diode the V18P rail is lifted (3.3 V - 0.7 V = ~2.6 V). We have seen this before.

I can't understand though why most boards are fine (1.8V).
Maybe soldering issue, short of V18P to V33 or Ground?

The rail being 0V (no voltage), I can not explain this. Could be a short to ground (soldering issue).
Also in this 0V case, there's no big current flowing from Vbat?

"

/MHv

Vijay
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Last seen: 1 month 13 hours ago
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Hi MHV,

Hi MHV,

For now, let's assume the other boards have soldering issues and leave them aside.

All the remaining boards that are fine before programming, measure voltages on rails V18, V18P, V12, V14 and V33 perfect.

V18 is used by external flash and the flash gets programmed fine.

V18P is used by RTC, motion sensor and environmental sensor chips. 

V33 is only used by a push button, nothing else.

The H/W schematic is the same as the DA14681 watch reference design and it already got reviewed by the Dialog team. Just the controller got replaced by DA14683.

After programming the code, the board is not drawing any excess current, NO SHORT CIRCUITS, NO PROBLEM. But the V18P reads random voltages like 2.6V. So we set all the pins power configurations and pin configurations as in the watch code. Now the V18P rail reads 0.4V instead of 2.6V. In both cases, the sensors on the bus can't work because they don't get the right voltage 1.8V.

If we erase the flash code, V18P rail measures 1.8V properly. External Flash, LEDs, and vibrator connected on a GPIO work fine, All boards show the same results.

So it looks to me like there is some configuration issue somewhere in the code or in the SDK!

Can you let me know how do I get 1.8V seen on the V18P rail after programming the boards?

Regards,

Vijay

 

MHv_Dialog
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Hi Vijay,

Hi Vijay,

Would you mind reaching out to the contact in Dialog that helped you with the review. They should be in a much better poisition to help troubleshoot this.

Thanks

 /MHv