SBVS372B December 2018 – August 2019 TPS7A25
For this design example, VOUT is set to 5 V. The following equations set the feedback divider resistors for the desired output voltage:
The control-loop error amplifier drives the FB pin to the same voltage as the internal reference (VFB = 1.24 V as listed in the Electrical Characteristics table). Use Equation 10 to determine the ratio of R1 / R2 = 3.03. Use this ratio and solve Equation 11 for R2. Now calculate the upper limit for R2 ≤ 1.24 MΩ. Select a standard resistor value for R2 = 1.18 MΩ.
Reference Equation 10 and solve for R1: