The resistors R1, R3, R6 etc attached to the high side of the gate drive mosfets BSS123 appears to be incapable of dissipating the required heat generated. Each of these 330 Ohm resistors is dropping around 11.8 V across it, or close to 38 mA. This means that 0.038^2 * 330 = 477 mW of power is being dissipated by these resistors. 0603 package resistors should only be handling 100 mW MAX power.
Is there a reason why this resistor was chosen so low or the package size incorrectly picked? Sizing the resistor up to 1210 package brings the thermal problem under control, but is obviously sub-optimal. Increasing the resistance to above 1.5k Ohm reduces the current such that it is under 100 mW dissipated.
Please advise.
The resistors R1, R3, R6 etc attached to the high side of the gate drive mosfets BSS123 appears to be incapable of dissipating the required heat generated. Each of these 330 Ohm resistors is dropping around 11.8 V across it, or close to 38 mA. This means that 0.038^2 * 330 = 477 mW of power is being dissipated by these resistors. 0603 package resistors should only be handling 100 mW MAX power.
Is there a reason why this resistor was chosen so low or the package size incorrectly picked? Sizing the resistor up to 1210 package brings the thermal problem under control, but is obviously sub-optimal. Increasing the resistance to above 1.5k Ohm reduces the current such that it is under 100 mW dissipated.
Please advise.