CN-121996597-A - Hot plug structure applied to output stage of transmitter circuit

CN121996597ACN 121996597 ACN121996597 ACN 121996597ACN-121996597-A

Abstract

The invention discloses a hot plug structure applied to an output stage of a transmitter circuit, which belongs to the field of I/O ports of integrated circuits and comprises an input end A, output ends Y, NMOS, NM 1-NM 7, PMOS (P-channel metal oxide semiconductor) tubes PM 1-PM 7, a data path, an enabling control module, pull-up driving front-stage control and pull-down driving front-stage control. Simple structure, compare in traditional structure effectively reduces the chip area.

Inventors

YU DAN
GAO GUOPING
HE LINGWEI
LI XIANZHANG

Assignees

中国电子科技集团公司第五十八研究所

Dates

Publication Date: 20260508
Application Date: 20260127

Claims (2)

1. The hot plug structure applied to the output stage of the transmitter circuit is characterized by comprising an input end A, an output end Y, NMOS, NM 1-NM 7, PM 1-PM 7 of PMOS (P-channel metal oxide semiconductor) tubes, a data path and enabling control module, pull-up driving front stage control and pull-down driving front stage control; The input of the data path and the enabling control module is connected with the input end A, the output C1 of the data path and the enabling control module is connected with the input of the pull-up driving front-stage control, the output VE is connected with the grid electrode of the PMOS tube PM2, the output C2 is connected with the input of the pull-down driving front-stage control, and the output VF is connected with the grid electrode of the NMOS tube NM 2; The output D1 of the pull-up driving front-stage control is connected with the drain end of the PMOS tube PM2 and the drain end of the PMOS tube PM4, and is simultaneously connected with the gate end of the PMOS tube PM1, the source end of the PMOS tube PM2 is connected with the substrate end, and is simultaneously connected with the source end, the substrate end and the gate end of the PMOS tube PM3, the source end of the PMOS tube PM4 is connected with the substrate end and the substrate end of the PMOS tube PM5, and is simultaneously connected with the substrate end, the gate end and the substrate of the PMOS tube PM5 of the PMOS tube PM4, the source end of the PMOS tube PM1 is connected with the source end, the gate end and the substrate of the PMOS tube PM6 of the PMOS tube PM1, and is simultaneously connected with the source end, the gate end and the substrate of the PMOS tube PM7 of the PMOS tube PM6, and the drain end of the PMOS tube PM3, the drain end of the PMOS tube PM5 and the drain end of the PMOS tube PM7 are respectively connected with the output Y; The output D2 of the pull-down driving front-stage control is connected with the drain end of the NMOS tube NM2 and the drain end of the NMOS tube NM4, and is simultaneously connected with the gate end of the NMOS tube NM1, the source end of the NMOS tube NM2 is connected with the substrate end, and is simultaneously connected with the source end, the substrate end and the gate end of the NMOS tube NM3, the source end of the NMOS tube NM4 is connected with the substrate end and the substrate end of the NMOS tube NM5, the gate end of the NMOS tube NM4 and the gate end of the NMOS tube NM5 are both connected with GND, the source end of the NMOS tube NM1 is connected with the source end, the gate end and the substrate of the NMOS tube NM6, and is simultaneously connected with the source end, the gate end and the substrate of the NMOS tube NM7, and the drain end of the NMOS tube NM6 is connected with GND, the drain end of the NMOS tube NM3, the drain end of the NMOS tube NM5 and the drain end of the NMOS tube NM7 are connected with the output Y.
2. The hot plug structure of claim 1, wherein the data path and enable control module outputs VE to be L level when the voltage at the output terminal Y is higher than VCC, and wherein the data path and enable control module outputs VF to be H level when the voltage at the output terminal Y is lower than GND.

Description

Hot plug structure applied to output stage of transmitter circuit Technical Field The invention relates to the technical field of integrated circuit I/O ports, in particular to a hot plug structure applied to an output stage of a transmitter circuit. Background With the continuous development of electronic communication technology in the industrial field and the wide application of computer networks, a transmitter circuit module applied to the field of interface circuits is often required to meet various special requirements, such as high-voltage resistance, backflow prevention and the like of ports. The RS-485 circuit is a typical application case, and the RS-485 bus standard manufactured by the electronic industry association in 1983 can meet the requirement of long-distance transmission. Compared with the characteristics of other bus technologies, the RS-485 uses balanced double-line transmission, has the advantages of strong noise immunity, high data transmission rate and high data transmission reliability, and supports multi-node and long-distance communication. Due to the fact that the RS-485 transmission distance is long, potential difference exists between the ground potentials of the transmitting end and the receiving end of the system, and the common mode output voltage meets the range of-7V to +12V. That is, the ports of the output device need to withstand voltages above the supply voltage and below ground, and no large reverse current flow occurs. When the method is particularly applied to a hot plug scene, as the integrated modules are more and the functions are more and more complicated in a large-scale electronic system. Plug and play of a single board becomes a common requirement in system application and also becomes a difficult problem to be solved in the design of a bus port circuit. For example, when a certain module fails, only the failed module needs to be plugged and replaced, so that the problem is rapidly solved. The hot plug use of the module circuit requires that the bus port can meet the hot plug function, namely, the circuit cannot burn out the circuit due to wrong conduction in the plug replacement process, and the main board power supply drop and bus signal abnormality cannot be caused. The output port of a typical RS-485 transmitter is often formed of high voltage devices in series, for example, pull-up drive stages, with floating substrate structures used for the high voltage devices in series. The substrates of the two serial devices are of back-to-back diode structures, namely, the backflow to the power supply can be prevented when the port voltage is higher than the power supply, and the port signal cannot be influenced by the power supply voltage through the substrates during normal operation. Likewise, the pull-down structure is a similar structure and principle. Although this configuration effectively satisfies the back-flow current problem of the ports, the series devices make the area of the driver stage four times larger than the single stage configuration. The smaller the size of the circuit, the lower the cost of the die, based on real world applications. It is desirable to design a single stage drive configuration that also prevents the bus from flowing back into the power supply current. Disclosure of Invention The invention aims to provide a hot plug structure applied to an output stage of a transmitter circuit so as to solve the problems in the background technology. In order to solve the technical problems, the invention provides a hot plug structure applied to an output stage of a transmitter circuit, which comprises an input end A, output ends Y, NMOS, NM 1-NM 7, PMOS (P-channel metal oxide semiconductor) pipes PM 1-PM 7, a data path, an enabling control module, pull-up driving front-stage control and pull-down driving front-stage control; The input of the data path and the enabling control module is connected with the input end A, the output C1 of the data path and the enabling control module is connected with the input of the pull-up driving front-stage control, the output VE is connected with the grid electrode of the PMOS tube PM2, the output C2 is connected with the input of the pull-down driving front-stage control, and the output VF is connected with the grid electrode of the NMOS tube NM 2; The output D1 of the pull-up driving front-stage control is connected with the drain end of the PMOS tube PM2 and the drain end of the PMOS tube PM4, and is simultaneously connected with the gate end of the PMOS tube PM1, the source end of the PMOS tube PM2 is connected with the substrate end, and is simultaneously connected with the source end, the substrate end and the gate end of the PMOS tube PM3, the source end of the PMOS tube PM4 is connected with the substrate end and the substrate end of the PMOS tube PM5, and is simultaneously connected with the substrate end, the gate end and the substrate of the PMOS tube PM5 of the PMOS tube PM4, the source end of th