ZHCSRR9K December 2003 – June 2024 TPS2061 , TPS2062 , TPS2063 , TPS2065 , TPS2066 , TPS2067
PRODUCTION DATA
請參考 PDF 數據表獲取器件具體的封裝圖。
The low on-resistance on the N-channel MOSFET allows the small surface-mount packages to pass large currents. The thermal resistances of these packages are high compared to those of power packages; it is good design practice to check power dissipation and junction temperature. Begin by determining the rDS(on) of the N-channel MOSFET relative to the input voltage and operating temperature. As an initial estimate, use the highest operating ambient temperature of interest and read rDS(on) from Figure 6-25. Using this value, the power dissipation per switch can be calculated by:
Multiply this number by the number of switches being used. This step renders the total power dissipation from the N-channel MOSFETs.
The thermal resistance, RθJA = 1 / (DERATING FACTOR), where DERATING FACTOR is obtained from the Dissipation Ratings Table. Thermal resistance is a strong function of the printed circuit board construction , and the copper trace area connecting the integrated circuit.
Finally, calculate the junction temperature:
Where:
Compare the calculated junction temperature with the initial estimate. If they do not agree within a few degrees, repeat the calculation, using the calculated value as the new estimate. Two or three iterations are generally sufficient to get a reasonable answer.