ZHCSI01C April 2018 – October 2019 LMR36006
The output voltage of LMR36006 is externally adjustable using a resistor divider network. The range of recommended output voltage is found in the table. The divider network is comprised of RFBT and RFBB, and closes the loop between the output voltage and the converter. The converter regulates the output voltage by holding the voltage on the FB pin equal to the internal reference voltage, VREF. The resistance of the divider is a compromise between excessive noise pick-up and excessive loading of the output. Smaller values of resistance reduce noise sensitivity but also reduce the light-load efficiency. The recommended value for RFBT is 100 kΩ; with a maximum value of 1 MΩ. If a 1 MΩ is selected for RFBT, then a feed-forward capacitor must be used across this resistor to provide adequate loop phase margin (see CFF Selection). Once RFBT is selected, is used to select RFBB. VREF is nominally 1 V.
For this 5-V example values are: RFBT = 100 kΩ and RFBB = 24.9 kΩ.