Example 2:
You can use the complete thermal model to calculated node temperatures. However, the results would not vary drastically from thermal calculation based on the simplified model for most products and i n most environments. Hence, it is entirely up you to decide how accurate the results are needed for each individual deign. Table 4 provides all thermal resistances for 6-in dip package phototriac.
Using equations 1-9, Table 4's thermal resistances, and assuming Figure 5's emitter and detector power dissipations, Table 5 shows the node temperatures when TA is known.
Regardless of the package size and type, the thermal analysis will need to be performed to ensure a solid design. To aid this process, Vishay provides detailed thermal characteristics for newly released optocouplers and solid-state relays (SSRs) that have total power dissipation of 200 mW and higher. This thermal data supplied allows you to more accurately simulate heat distribution and thermal impedance for optocoupler and SSR devices and thus avoid the problems that can arise when thermal parameters are exceeded.
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