Tool/software:
Hi Team,
We are planning to use the TPS552892QWRYQRQ1 buck-boost converter in our design. I’ve completed the design calculations using both the TI calculation sheet and Webench tool for our use case.
Design Requirements:
- Input Voltage (Vin): 8V to 14.6V
- Output Voltage (Vout): 5V @ 4A
- Switching Frequency: 580 kHz
- Ambient Temperature: 0°C to 40°C
While working in Webench, I observed that increasing the sense resistor value affects the junction temperature (Tj) of the IC. However, ther is no change in Tj while increasing the sense resistor value in the TI calculation sheet. Could you please clarify why this discrepancy occurs?
Additionally, under worst-case conditions (Vin = 8V, Vout = 5V @ 4A), the estimated junction temperature rise is 65°C, resulting in a total Tj of 105°C (ambient + rise).
- Will this temperature pose a reliability concern if the IC operates continuously over long periods?
- What measures can be taken to reduce the junction temperature? I’ve attached the calculation sheet for your review. Kindly share your feedback and suggestions. https://docs.google.com/spreadsheets/d/1tI4ZOMrjlrJ_sg2p3krIE8ADRA-O3ct2/edit?usp=drive_link&ouid=116196912063216638177&rtpof=true&sd=true