ZHCSIE2M June 2008 – June 2018 TPS735
PRODUCTION DATA.
Using the thermal metrics ΨJT and ΨJB, as the table shows, the junction temperature can be estimated with corresponding formulas (Equation 5), which are more accurate than the value of TJ through calculation with θJA.
where
NOTE
Both TT and TB can be measured on actual application boards using a thermo‐gun (an infrared thermometer).
For more information about measuring TT and TB, see Using New Thermal Metrics, available for download at www.ti.com.
According to Figure 24, the new thermal metrics (ΨJT and ΨJB) do not depend on the copper area. Using ΨJT or ΨJB with Equation 5 can estimate TJ by measuring TT or TB on an application board.