TPS3890: resistor divider

Connie Lu1

Intellectual 2080 points

Part Number: TPS3890

Hi team,

For the TPS3890, my customer would like to use the 3V fixed version, but only the 2.5V version is available.

Can customer add an external resistor to modify the 2.5V to 3.0V? Can you please confirm whether this is an option and if so, what external resistor should they use to adjust the voltage to 3V?

Thanks,

Connie

over 2 years ago

0 Jake F over 2 years ago

TI__Intellectual 1210 points

Hi Connie,

This is possible, but be aware that adding external resistors will introduce more accuracy error. Also, use resistors in the 10s of KOhm range so that the resistance seen from sense to ground is dominated by the external resistors rather than the internal divider.

Jake

0 Connie Lu1 over 2 years ago in reply to Jake F

TI__Intellectual 2080 points

Thanks Jake.

What values are the internal resistors for the 2.5V?

+1 Jake F over 2 years ago in reply to Connie Lu1

TI__Intellectual 1210 points

Hi Connie,

The exact values are not made known to me at this time. Based off of the information from the datasheet though, a good estimate can be reached. In the EC table, the Isense input current can be used for a calculation:

Jake

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TPS3890: resistor divider