Electronics
M. Karimi; D. Dideban
Abstract
Background and Objectives: The H-bridge (HB) driver design with high efficiency is one of the most challenging issues in power systems that drive AC/DC loads. HB driver circuit based upon complementary MOSFET type used as a driving system of DC motor, power converters, and battery charger for electrical ...
Read More
Background and Objectives: The H-bridge (HB) driver design with high efficiency is one of the most challenging issues in power systems that drive AC/DC loads. HB driver circuit based upon complementary MOSFET type used as a driving system of DC motor, power converters, and battery charger for electrical vehicles. In Driving DC motors, dead-time (DT) generation has been considered a major factor such as preventive power line short-circuit (shoot-through) over high and low-side MOSFETs. In this paper, the HB driver is designed for linear actuators with consideration for the prevention of shoot-through.Methods: The propagation delay of logic gates are used to postpone the arrival gate drive signal for high/low side MOSFETs resulting in short circuit elimination on the DC source. Results: As mentioned, logic gates’ propagation delay by their values causes interruption between the high and low-side power switches gate drive signal resulting in shoot-through elimination. Although the existence of DT influences the performance of the rotational speed and output torque of a DC motor by increasing the distortion and pulse interval, Linear actuators due to low-velocity linear motion do not require the PWM control, therefore DT has no substantial effect on driver performance. Conclusion: Simulation and experimental results validate the method proposed in this paper. According to the specifications of the circuit designed in this paper, for loads that do not need rotational speed control, logic gates with proper propagation delay can be chosen to eliminate short circuits in complementary MOS switches without requiring DT compensation methods.
Electronics
M. Karbalaei; D. Dideban; N. Moezi
Abstract
Background and Objectives: In this work, a dual workfunction gate-source pocket-retrograde doping-tunnel field effect transistor (DWG SP RD-TFET) is proposed and investigated.Methods: The dual workfunction gate-source pocket-retrograde doping-tunnel field effect transistor is a Silicon-channel TFET with ...
Read More
Background and Objectives: In this work, a dual workfunction gate-source pocket-retrograde doping-tunnel field effect transistor (DWG SP RD-TFET) is proposed and investigated.Methods: The dual workfunction gate-source pocket-retrograde doping-tunnel field effect transistor is a Silicon-channel TFET with two isolated metal gates (main gate and auxiliary gate) and a source pocket in the channel close to the source-channel junction to increase the carrier tunneling rate.Results: For further enhancement in the tunneling rate, source doping near the source-channel junction, i.e., underneath the auxiliary gate is heavily doped to create more band bending in energy band diagram. Retrograde doping in the channel along with auxiliary gate over the source region also improve device subthreshold swing and leakage current. Based on our simulation results, excellent electrical characteristics with ION/IOFF ratio > 109, point subthreshold swing (SS) of 6 mV/dec and high gm/ID ratio at room temperature shows that this tunneling FET can be a promising device for low power applicationsConclusion: In order to increase the ON-current in this device, we utilized several methods including incorporation of high-K material in top oxide, source pocket in channel and a thin auxiliary gate with high workfunction over the source region. Incorporating auxiliary gate over the source also caused a barrier formation in the energy band diagram profile of this device which it leds electron concentration in the channel, subthreshold swing and OFF-current to be reduced.
