Diode-Clamped Linear Amplifier using n-channel MOSFET and Crossover Distortion Compensation Method

Abstract

This paper proposes a new diode-clamped linear amplifier (DCLA) topology using only n-channel MOSFETs. Although the conventional DCLA consists of n and p-channel MOSFETs, the proposed DCLA is composed of n-channel MOSFETs. Therefore, the proposed DCLA is easy to develop, because selection of complementary pair MOSFETs is not needed. As with the conventional DCLA, noise level of output voltage of the proposed DCLA is lower than general pulse width modulation (PWM) inverters, because the DCLA uses multilevel topology and active state of MOSFETs. Additionally, this paper also proposes a method of voltage feed-back control, which is capable of compensating crossover distortion of the DCLA. The output voltage of the DCLA has crossover distortion that causes the increase of voltage error and total harmonic distortion (THD). In order to compensate the crossover distortion, a voltage compensator including a plant model for the proposed DCLA is implemented. The proposed method reduces THD of output voltage by 90 percent through the simulations and experimental results.