JAJSHT6E August 2019 – September 2022 TPS7A24
PRODUCTION DATA
For this design example, VOUT is set to 5 V. The following equations set the output voltage:
For improved output accuracy, use Equation 9 and IFB(TYP) = 10 nA as listed in the Section 6.5 table to calculate the upper limit for series feedback resistance, R1 + R2 ≤ 5 MΩ.
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 Section 6.5 table). Use Equation 8 to determine the ratio of R1 / R2 = 1.66. Use this ratio and solve Equation 9 for R2. Now calculate the upper limit for R2 ≤ 1.24 MΩ. Select a standard value resistor of R2 = 1.18 MΩ.
Reference Equation 8 and solve for R1:
From Equation 10, R1 = 1.96 MΩ can be determined. From Equation 8, select VOUT = 3.299 V.