The invention discloses a RS232
communication interface circuit that supports
hot swapping. The interface circuit uses a high-speed
operational amplifier as a core device, and is equipped with corresponding
peripheral devices to form a
voltage buffer; a three-stage tube is used as an
inverter, and the phase is reversed twice consecutively. , obtain the same phase transmission level, and also realize the wide
voltage range of the interface circuit, meet the requirements of the RS232 communication
frequency band, realize the hot swap of the
serial port circuit, and meet the
voltage requirements between different devices and different
signal levels. The power supply circuit of the interface circuit can follow the input voltage, and can overcome the
surge voltage and surge current during the
hot swapping process. The invention has high integration degree, small volume,
simple circuit connection mode and low
failure rate. In the case of failure, it can also facilitate fault detection and analysis, and troubleshoot and repair. The invention can be used in the transmission of different
signal levels of each RS232, and has level conversion,
signal buffering, hot plug function and high reliability.