The invention relates to the technical field of electronic circuits, and provides a
programming port and dimming port shared circuit which comprises a dimming circuit, a main
control circuit, a power supply circuit, a burning circuit, a switching circuit, a first port and a second port, the first port serves as a common port of positive dimming signals and burning signals, and the second port is used for being connected with an external dimming
signal cathode. The
signal receiving end of the dimming circuit is connected with the first port, the second port is grounded, the burning port of the main
control circuit is connected with the first port through the burning circuit, the output end of the power supply circuit provides a working power supply for the main
control circuit, when the
system power supply works, the switching circuit is switched off, and the
system power supply supplies power to the power supply circuit, and when the
system power supply does not work, the switching circuit is switched on. The burning
signal supplies power to the power supply circuit; according to the invention, by optimizing the power supply design and utilizing the original power supply logic, the normal dimming of the power supply during working is ingeniously realized, and the off-line
programming function can be realized when the power supply does not pass through.