LED display device, driving method and chip thereof

Disclosed is an LED display device, a driving method and a chip thereof. The LED display device comprises: a display array comprising row lines, column lines, and pixel units each comprising an LED connected to a corresponding one of the row lines and a corresponding one of the column lines; a row driver module, connected to the row lines and providing selection signals; a column driver module, connected to the column lines and providing driving signals corresponding to gray scale data according to pulse width modulation signals; a channel control module, connected to the column lines and adjusting a column-line voltage of a corresponding column line to a target voltage in a first time period when a corresponding pulse width modulation signal is active, thus improving constant current cut-in speed and improve consistency and linearity under low gray scale when an image with low gray scale is displayed.