Wrong ADC Valueswhen VBAT is below 3V

Klaus Nikolaus

Other Parts Discussed in Thread: CC3200

Hi,

we like to monitor the battery voltage of CC3200 application with a voltage divider on ADC1.

VBAT is 2xAA --> 2.4...3.2V

Voltage divider: 1k5 / 1k0

When VBAT is higher than 3V the measured battery voltage is ok, but when VBAT is below 3V we still measure 3.0 .. 3.1V.

When we pull ADC in to GND we measure 0V when VBAT > 3.0V and 0.55V for example when VBAT = 2.5V.

It seems really strange and we do not know what to do.

Thanks for any help on this issue!

Klaus

0 LAXMI KANT TIWARI over 9 years ago

Genius 3345 points

Did you remove J13, It disconnect DC regulator when board is powered by Battery. If not remove it and then check your output.

0 Klaus Nikolaus over 9 years ago in reply to LAXMI KANT TIWARI

We have our own hardware, so there is no J13 and there is only the battery as supply.

0 Klaus Nikolaus over 9 years ago in reply to LAXMI KANT TIWARI

We have our own hardware only supplied with battery.

Regadrs,
Klaus

0 Klaus Nikolaus over 9 years ago

It was a defect on our hardware. We assume that we crashed the ADC1 Input with 3V.

After building up a second hardware all ADC values (VBAT 2.4...3.3V) are ok.

0 LAXMI KANT TIWARI over 9 years ago in reply to Klaus Nikolaus

Genius 3345 points

Thats great...

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