Wu Xiulong

A circuit macromodel of high voltage LDMOS based on numerical simulation

Lateral double-diffused MOSFET (LDMOS) is widely used in power integrated circuits and microwave integrated circuits. So creating equivalent circuit of LDMOS is becoming more important. The previous models divided the on-state region of LDMOS into two parts, linear region and saturation region. The formulas and equivalent circuits are very complicated. This paper presents an I-V equation that is available in the whole on-state region by numerical simulation, and creates a macromodel of LDMOS circuits. The model contains fewer parameters that are easily extracted. Then we obtain a simpler equivalent circuit. Convergence becomes easier when using this equivalent circuit to simulate power integrated circuits. In the end, we give an application of our model.

A New Design of Voltage Controlled Oscillator

This paper designed a new low phase noise voltage- controlled oscillator (VCO) with harmonic filtering resistor and source damping resistor. The author analyzed and modulated the results by the simulator of Mentor Graphics in a 0.35-um CMOS process, and achieved the optimization scheme in the end. The simulation result shows the VCO can reach a phase noise of - 124.9 dBc/Hz at 1 MHz offset while working at 4.6 GHz in a 3 mA excursion current. During the 0 to 3 controlled voltage the tuning range can reach 18.5%, and the power consumption is only 7.09 mW.

A Macromodel of MOSFET for Deep Submicron Analog Circuit Simulation

The previous models and equivalent circuits of deep submicron MOSFET are extremely complicated, for diversified short-channel effects. Based on the nonlinear resistances of devices, we get an I-V equation and create a simple equivalent circuit macro-model. Compared with the previous models, the equation is an analytic expression and has fewer parameters and no discontinuous point of linear and saturation regions .The convergence becomes easier and the calculated speed becomes faster when the equivalent circuit macro-model is used to simulate the low voltage analog IC. In the end, we give an application of our model to validate the accuracy.