In the LMR436x0-Q1 family, an adjustable output or fixed output voltage option is configurable for every device variant (see Section 5). For an adjustable output, the user needs an external resistor divider connection between the output voltage node, the device FB pin, and the system GND, as shown in Figure 8-9. The adjustable output voltage operation utilizes a 1-V internal reference voltage. Refer to section Section 18.104.22.168.1 for more details on how to adjust the output voltage.
When using the fixed-output configuration from the LMR436x0-Q1 family, simply connect the FB pin (will be identified as VOUT/FB pin for fixed-output variants in the rest of the data sheet) to the system output voltage node. See Section 5 for more details.
In an adjustable output voltage configuration, an addition feedforward capacitor, CFF, in parallel with the RFBT, can be used to optimize the phase margin and transient response. See Section 22.214.171.124 for more details. No additional resistor divider or feedforward capacitor is needed in fixed-output variants.