D类音频功率放大器中的死区控制电路设计

设计了一种用于D类音频功率放大器中产生死区时间的互锁电路,通过对功率管的输出状态进行检测,使得在每种状态下只有一个功率管导通,有效地防止了上下功率管的同时导通,从而减小了功率级的损耗,提高了放大器的效率.针对该互锁电路提出了一种死区时间设计方法,使得在有效抑制功率管导通的同时引入最小的失真,同时对引入死区时间所产生的影响做了详细分析.仿真结果表明:该互锁电路在输出信号的上升沿产生的死区时间为13.6 ns,在输出信号的下降沿产生的死区时间为15.5 ns.

Design of dead time control circuit for a class D audio power amplifier

A deglitch circuit for Class D audio power amplifier was presented to control the dead time,which can prevent large shoot-through currents from passing through H-bridge.The deglitch circuit allows only one power metallic oxide semiconductor field effecttransistor(MOSFET) work at a time by supervising the state of output stage,which can reduce the dissipation of power stage and improve the efficiency.A design method of dead time was proposed for the deglitch circuit to reduce the distortions introduced by the dead time.The influence of the dead time was also presented.Simulation results show that the dead time is designed to 13.6 ns for the leading edge and 15.5 ns for the trailing edge.