Signal transmitting circuit

The invention relates to a signal transmitting circuit. When a circuit is provided with a filter circuit, a charging discharging control circuit and a state control circuit are set, and then three states of level changing, high level, low level, and high impedance state, can be realize don a communication line. The charging discharging control circuit is used to realize rapid charging dischargingof a filter capacitor, and the state control circuit is used to output the high impedance state during receiving of signals, and therefore signal transmission of other devices of a bus cannot be affected. The anti-electromagnetic interference characteristics of the circuit can be guaranteed, and therefore communication efficiency can be improved. 本发明涉及种信号发送电路，在所述电路中设置有滤波电路的同时，设置充放电控制电路、状态控制电路，使得通信线上可以实现三种状态电平变换：高电平，低电平和高阻态；通过充放电控制电路实现滤波电容的快速充放电，以及通过状态控制电路使得在接收信号的时候输出高阻态，不影响总线上其它设备发送信号；由此不仅保证了电路的抗电磁干扰的特性，同时提高了通信的效率。