This article is objected to present a new fully/electronically controllable voltage-mode Schmitt trigger based on a modified voltage differencing gain amplifier (VDGA). It can offer both counterclockwise (CCW) and clockwise (CW) functions, without changing circuit topology. The proposed Schmitt trigger comprises merely one VDGA and three resistors. The hysteresis and amplitude of the output voltage of proposed Schmitt trigger can be independently controlled by corresponding bias currents of the VDGA. The modified VDGA was designed by a fully balanced differential transconductance technique based on 0.35 µm CMOS transistor technology, providing advantages in high gain, wide range of adjustability and symmetrical output signals. The performances of proposed Schmitt trigger were deeply investigated by not only simulation via PSpice program, but also experimental setup using commercially available integrated circuits. Both results agree well with the theoretical anticipation and are consistent each other. The total power consumption is approximately 1.39 mW at ± 1.5 V power supply. Additionally, to prove the practical use-abilities of the proposed Schmitt trigger, its applications in a voltage-mode relaxation oscillator, a triangular/square wave generator and a pulse width modulator are also included.

本文的目的是提出一种基于改进的压差增益放大器（VDGA）的新型完全/电子可控电压模式施密特触发器。它可以提供逆时针（CCW）和顺时针（CW）功能，而无需更改电路拓扑。提出的施密特触发器仅包括一个VDGA和三个电阻。建议的施密特触发器的输出电压的磁滞和幅度可以通过VDGA的相应偏置电流独立控制。修改后的VDGA采用基于0.35 µm CMOS晶体管技术的完全平衡差分跨导技术设计，具有高增益，宽范围可调节性和对称输出信号的优势。不仅通过PSpice程序进行仿真，还对拟议的施密特触发器的性能进行了深入研究，以及使用市售集成电路的实验装置。两种结果均与理论预期相符，并且彼此一致。在±1.5 V电源下，总功耗约为1.39 mW。另外，为了证明所提出的施密特触发器的实际使用能力，还包括其在电压模式张弛振荡器，三角/方波发生器和脉冲宽度调制器中的应用。