UCD90320: How much current flows into AMON pin for UCD90320 when IC operating.

user6013811

Prodigy 170 points

Part Number: UCD90320

Hi Sir,

Can we know how much current flows into AMON pin on UCD90320?

We have a 3.0V power supply, using 511k ohm and 1M ohm to divide the voltage into 1.98V to the AMON pin of UCD.

And we found the 1.98V voltage of divide drop about 1V when the UCD power on.

We think that a part of uA current flows to the UCD and causes the voltage to drop, which leads to Deviation in the voltage of measurement on the UCD.

Is AMON pin current that flows to UCD increased when monitor voltage go high? High bit(high voltage of monitor) mean there are more circuit of ADC sampling inside the chip, so the current increase, is this correct?
In addition, we will use Mega ohm to divide the voltage because of we need to save power for battery use. Is there any suggestion for this design?

Many thank

over 4 years ago

0 Anne Ngo77 over 4 years ago

TI__Genius 9310 points

Hi,

I will find the answer and response to you asap.

Thanks for using the part and for your patient.

Anne Ngo

Texas Instruments

0 yihe over 4 years ago

TI__Guru 65710 points

The leakage current of the AMOX is up to 2uA. so the mega ohm resistor is too high for the device. Please adjust resistor value accordingly.

The leakage current does not change with the input voltage and the max input voltage is decided by the ADC reference which is 3.3V(internal) or 3V(external).

Regards

Yihe

0 user6013811 over 4 years ago in reply to yihe

Prodigy 170 points

Do you mean it will always leak 2uA current on AMON pin when UCD90320 power on and use it, is this correct?

0 yihe over 4 years ago in reply to user6013811

TI__Guru 65710 points

It is up to 2uA once the AMON is used.

Regards

Yihe

Power management

Power management forum

UCD90320: How much current flows into AMON pin for UCD90320 when IC operating.