ZHCSBP7C October 2013 – December 2018 TPS24750 , TPS24751
UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
Next, select the values of the OV and UV resistors, R1, R2, and R3, as shown in the typical system application diagram Figure 41 . From the TPS2475x electrical specifications, VOVTHRESH = 1.35 V and VENTHRESH = 1.35 V. VOV is the overvoltage trip voltage, which in this case is 14 V. VUV is the undervoltage trip voltage, which for this example equals 8.4 V.
Assume R3 is 1.5 kΩ and use Equation 12 to solve for (R1 + R2). Use Equation 13 and the (R1 + R2) from Equation 12 to solve for R2 and finally for R1. From Equation 12, (R1 + R2) = 14.05 kΩ. From Equation 13, R2 = 1 kΩ and R1 = 13.05 kΩ. Scaling all three resistors by a factor of ten to use less supply current for these voltage references and using standard 1% resistor values gives R1 = 130 kΩ, R2 = 10 kΩ, and R3 = 15 kΩ.