The output voltage of the LM76002/LM76003 device is externally adjustable using a resistor divider network. In the application circuit of Figure 22, this divider network is comprised of top feedback resistor RFBT and bottom feedback resistor RFBB. Equation 15 is used to determine the output voltage of the converter:
Choose the value of the RFBT to be around 1 MΩ to minimize quiescent current during light load operation or 100kΩ to improve noise immunity. With the desired output voltage set to be 3.3 V and with a VFB = 1 V, the RFBB value can then be calculated using Equation 15. The formula yields a value of 434.78 kΩ. Choose the closest available value of 432 kΩ for the RFBB, or a combination of two resistors (432 kΩ + 2.74 kΩ) to increase initial accuracy.