ZHCSJG2A March 2019 – September 2019 TPS7A78
PRODUCTION DATA.
Given the maximum AC supply voltage and the minimum frequency for this application example, the calculated ISHUNT current using Equation 1 from the Standby Power and Output Efficiency section yields:
NOTE
The Recommended Operating Conditions table does not specify the maximum AC voltage that can be used because the maximum VAC voltage is bound by the maximum ISHUNT current and the availability of the high-voltage cap-drop capacitor.
The RMS power given in Equation 13 and the peak power given in Equation 14 must be used to determine the power rating of the surge resistor RS.
Using Equation 13 and Equation 14 yields the following RS power ratings:
Use the power rating resulting from Equation 14 because this equation yields a higher power requirement. Furthermore, additional margin is always a good design practice.