We are planning to use the is part as a gate driver for an RF MOSFET class E amplifier running at 250 MHz which is at 50% duty cycle. The rise and fall times are appropriate although the data sheet states the part is suitable for up to 60 MHz operation. The load is 50-75pF for the Ciss of the MOSFET being switched.
One issue we are seeing in LTspice simulation are that the current is not at all agreeing with the data sheet, it is a factor of 4-10 lower. Any thoughts of why that is?
The other concern we have is power dissipation. Scaling the current Idd,op by frequency, the Idd at 250 MHz and 100pF load should be close to 400mA, so about a 2W dissipation. Without a heatsink to the case, it would seem like an overheating condition. Any thoughts on how to heat sink such a small part? It would have to be a heat sink to the case, as the junction to board thermal resistance is 30-40 C/W. Lowering the capacitive load should reduce the power consumption of course, but not sure about the internal design and if that is going to be significant.
The board thermal resistance would be better for the LMG1025, but then the bond wire inductance is higher, so not sure if it is even an option at 250 MHz and with the 50-75 pF load cap?
