3 Replies Latest reply on Dec 7, 2017 10:55 AM by wejoc_1309221

Excessive power consumption on battery?

wejoc_1309221 Dec 5, 2017 1:07 AM

I've been doing quite a few measurements on the power consumption of the CY8CKIT-062-BLE kit, and I can't make any real sense of it yet.

When running the sample Capsense + e-Ink sleep demo the board consumes a minimum of 30mA at all times (more when the MCU and e-Ink actually is awake).

Powering the board from the Vin pins the minimum is now 35mA and moving on to power the entire board including programmer from the USB-C connector we're right at 100mA.

The schematics shows some oddities regarding the battery charger hookup. When powered from battery (the J15 connector), the battery charger IC boosts the battery voltage to 5V. A few diodes later and this voltage is shunted back to charger input of the same IC, which seems to trigger charging (which in turn immediately kills the boost regulator and then the charging stops, rinse and repeat). There's a distinct whining from a coil (I suspect L6 but not 100% certain yet) when powering the board this way.

Anyone else experiencing this? I've been investigating this on and off for the past two weeks and I'm running out of ideas. A hardware modification seems inevitable at this point, the question is just where to perform the smallest mod possible getting rid of this insane sleep consumption.

Any hints are appreciated!

/wj

1. Re: Excessive power consumption on battery?

RyanZ_36 Dec 6, 2017 5:06 PM (in response to wejoc_1309221)

Hi Werner,

Not sure the exact reason.
How about CE219881_PowerModes example code in PSoC Creator? Does it work?
Kindly follow its user guide. It requires some steps for hardware setup.

Thanks,
Ryan
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2. Re: Excessive power consumption on battery?

wejoc_1309221 Dec 6, 2017 11:52 PM (in response to RyanZ_36)

Thanks Ryan, I haven't tested PowerModes but will give it a shot and report back!!

/wj
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3. Re: Excessive power consumption on battery?

wejoc_1309221 Dec 7, 2017 10:55 AM (in response to RyanZ_36)

Unfortunately it still looks really bad on the supply side. The PowerModes code runs fine as can be seen in the screenshot where the "ADC" graphs show the core voltage (3.3V setting) and the core current in deep sleep, then active, low-power active, active again and finally deep sleep again.

The issue is the 30-or-so odd mA consumed somewhere else, as can be seen in the current measurement at the Vin terminals (graphs named Main Voltage/Current) in this case, battery terminals show very similar waveforms.

I couldn't find any special hardware setup steps in the user guide CE219881.pdf that was installed as part of the example project (Document number 002-19881 Rev.*A)?
/wj
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