This paper proposes a class-C digitally controlled oscillator (DCO) using constantly-conducting NMOS biased switchable capacitor, aiming to optimize the off-state quality factor, reduce the off-state capacitance and improve the oscillator transient behavior. The DCO is fabricated in a 28 nm CMOS technology. With a unitary-weighted SC bank, the DCO shows an inherently monotonic tuning with a range of 8.2-11.1 GHz (30.1%), and a very fine tuning resolution of 40kHz. The class-C DCO achieves -115.5 dBc/Hz phase noise at 1 MHz offset from 10 GHz carrier frequency with 23 mW, resulting in a -182 dBc/Hz FoM and -191.5dBc/Hz FoMT.

This work presents a reference frequency and current generator circuit with high stability to temperature and process variations without requiring any post-fabrication trimming. The design serves as the reference generator in an active gate driver IC for Silicon Carbide transistors. It incorporates an 8MHz relaxation oscillator and a 12μA self-calibrating current reference. Both circuits share a parallel-connected discrete off-chip resistor and capacitor to eliminate the impact of on-chip process variations. A temperature stability of 45ppm/°C for the frequency and 54ppm/°C for the current is achieved by applying a closed-loop comparator error feedback as well as a resistor temperature compensation. The overall frequency and current standard deviation for process variations is 0.70% and 0.47%. The circuit is fabricated in a 0.18μm BCD technology.

This paper presents the design of a high-voltage (HV) single-inductor multiple-output (SIMO) fixed frequency DC-DC Buck converter for the power management unit of a Gate-Shaping digital gate driver for Silicon-Carbide power MOSFETs. Through shaping the switching waveform which drives the power MOSFET there are significant improvements regarding energy efficiency and electromagnetic compatibility achievable. Driving the gate of the power MOSFET the gate driver is provided with a galvanically isolated power supply of 20 V. Thus, the 0.4 W HV SIMO buck converter generates the internal 5 V and 1.8 V voltage rails required by the gate driver from the 20 V isolated power supply. It can provide up to 60 mA on each rail for analog and digital signal processing as well as driving the internal power MOSFETs. The design has been fabricated on an area of 0.6 mm2in a 0.18 µm HV BCD technology. In measurements it provides an average efficiency of 81.16 % over the whole operating range and a measured maximum efficiency of 87.44 %.