buck boost resistor divider help

Discussion in 'General Electronics Chat' started by cheesesandwich, Jan 18, 2011.

  1. cheesesandwich

    Thread Starter New Member

    Jan 18, 2011

    I am designing a circuit that should allow the adjustabilty of the output power. I am using a TI TPS63020 IC that uses a resistor divider to set the output voltage. I want to connect a simple slider switch that will allow adjusting the output power (watts). The problem is that the output resistance will vary between 1.3 ohms and 4 ohms. So I need a way to monitor the output resistance and use this value to change the resistor divider to change the VOUT so that the output power is fixed at an adjustable value by way of a multiposition switch. The resistor divider is shown on the FB pin on the attached pic.

    anyone have any ideas how to do this as easy as possible with adding as few of components as possible?