7.3.10 Thermal Derating

The LM3102 can supply 2.5 A below an ambient temperature of 100°C. Under worst-case operation, with either input voltage up to 42 V, operating frequency up to 1 MHz, or voltage of the RON pin below the absolute maximum of 7 V, the LM3102 can deliver a minimum of 1.9-A output current without thermal shutdown with a PCB ground plane copper area of 40 cm², 2 oz/Cu. Figure 22 shows a thermal derating curve for the minimum output current without thermal shutdown against ambient temperature up to 125°C. Obtaining 2.5-A output current is possible by increasing the PCB ground plane area, or reducing the input voltage or operating frequency.

Figure 22. Thermal Derating Curve