SLVSDA7E February 2017 – August 2019 TPS61178
The output voltage of the TPS61178 is externally adjustable using a resistor divider network. The relationship between the output voltage and the resistor divider is given by Equation 4.
Choose RDOWN to be approximately 80.6 kΩ. Slightly increasing or decreasing RDOWN can result in closer output voltage matching when using standard value resistors. In this design, RDOWN = 80.6 kΩ and RUP = 1000 kΩ, resulting in an output voltage of 16 V.
For the best accuracy, RDOWN is recommended to be smaller than 100 kΩ to ensure that the current following through RDOWN is at least 100 times larger than FB pin leakage current. Changing RDOWN towards the lower value increases the robustness against noise injection. Changing the RDOWN towards the higher values reduces the quiescent current for achieving higher efficiency at the light load currents.