Other Parts Discussed in Thread: UCC28C44
Hi team,
A customer is using our UC2844A in their system, and they meet some issue of thermal now. 3 questions here, I found confused too, so I ask you for help:
1. According to junction temperature calculation method: Tj = Tc + Psi(JC)* power dissipation, customer knows the Tj from datasheet, Psi(JC) is given in datasheet, Tc is tested by customer, how to get the recommended power dissipation (Not the absolute value, which is 1W) from our datasheet? I mean in our datasheet, it lists:
Since customer can only refer to specs in the listed electrical characteristics, what's the Tc range condition here? and what's the power dissipation condition here?
2. Also about the datasheet section 7.5 figure above, it shows Ta=Tj, how to understand this? does this mean all the parameters in section 7.5 are tested in no-load condition? but some parameters must use a load.
3. About the Ta in datasheet section 7.3 (Recommended Operating Condition), and in section 7.5 (Electrical Characteristics).
In Section 7.3, Ta recommended is -40C to 125C. In section 7.5, Ta is tested from -40C to 85C. so if customer's Ta is in 85C to 125C, what performance may our chip have? Does the 125C Ta has some relation to 150C Tj?
Thank you!
Joel Li
