BQ25895: NTC input circuit details request

FFabio

Part Number: BQ25895

Dear teams,

I kindly ask you some details about the internal stage used into the BQ25895RTWR at the TS pin used to measure the NTC voltage at the divider network.

I would like to calculate for my checking the NTC resistance value by measuring the VREGN and the voltage at the TS pin, because I know the RT1 and RT2 values I'm able to perform a calculation about the NTC resistance, but to be sure about it I kindly ask you some details about the input impedance at the TS pin..

Thanks and best regards.

over 4 years ago

0 Wyatt Keller over 4 years ago

TI__Guru** 105760 points

Hello,

You should be able to use the Excel spread sheet to calculate the RT1 and RT2 values. I will check what the expected input impedance is.

Sincerely,

Wyatt Keller

slurax7a.zip

0 FFabio over 4 years ago

Expert 1455 points

Dear Keller,

thanks for your reply, I've already used the Excel tool to find the RT1 and RT2 with my NTC data that is not the standard NTC as used into the datasheet example.
Actually I'm using:

RT1=5230

RT2=29400

Thanks and best regards.

+1 Wyatt Keller over 4 years ago in reply to FFabio

TI__Guru** 105760 points

Hello,

If those are your values you can consider the input impedance as near infinite input resistance, if you had higher calculated values for RT1 and RT2 then it may influence.

Sincerely,

Wyatt Keller

0 FFabio over 4 years ago in reply to Wyatt Keller

Expert 1455 points

Thanks !

Best regards.

Power management

Power management forum

BQ25895: NTC input circuit details request