Post Date : Jul 11, 2023 / Last updated : Aug 21, 2023

Here explains how to estimate the junction temperature using Web DC/DC simulation.

1. Execution of simulation (select the IC / input the power supply specifications)

Input the simulation conditions for the input items and execute the simulation.

Step 1. Select a product
Step 2. Select oscillation frequency
Step 3. Select an operation mode
Step 4. Input the power supply specifications (Vin / Vout / Iout / peripheral component values etc.)

2. How to calculate / estimate the junction temperature

It is possible to confirm the junction temperature from "Summary" tab or "Efficiency / Tj / Duty" tab. For the junction temperature at each output current, confirm "Efficiency / Tj / Duty" tab.

Let's confirm the junction temperature when Vin = 5V / Vout = 3.3V / Iout = 2A/Ta = 25°C with XCL212 series as a concrete example.
You can see that the junction temperature is 92.23°C when Ta = 25°C and Vin = 5V / Vout = 3.3V / Iout = 2A under these conditions.

3. Calculation of junction temperature: change of ambient temperature / change of thermal resistance

For the actual design / evaluation, it is sometimes necessary to forecast the junction temperature at high ambient temperature or estimate the junction temperature giving consideration to heat dissipation of board.

In these cases, it is possible to estimate the junction temperature at high temperature or when the thermal resistance is different by just changing the value of input items "Ambient temperature: Ta" and "Thermal resistance: θja".