Analysis of LDMOS for effect of finger and device-width on gate feedback charge

Abstract

In this paper, we have simulated and analyzed the effect of fingers, device-width and main power supply (Vdd) on gate feedback charge (Qgd) and switching time of LDMOS by gate charge test circuit simulation. Gate feedback charge is the charge which is required to fill the gate-drain “Miller” capacitance. Smaller area will have smaller charge and switching time. It has been seen in our simulation that gate feedback charge (Qgd) and switching time increased more linearly with device width rather than no. of fingers and main power supply (Vdd). We have successfully simulated that to improve the device's power by increased the area, multi finger design is better than the width extension due to the lower gate feedback charge and faster switching time.