An improved differential signaling scheme for the chip-on-glass application of TFT-LCD

An improved signaling scheme for the intra-panel interface for the chip-on-glass (COG) application is proposed. The proposed signaling scheme adopts a transmitter with the current-mode driver with shunt termination for an impedance matching on the transmitter and a receiver without termination to eliminate the multiple reflections on the transmitter. It obtains good signal quality on the receiver without additional current consumption. The transmitter for the proposed signaling scheme adopts the current-mode driver with shunt termination instead of the voltage-mode driver with series termination resistor for minimizing the effect caused by the process dependency of the circuitry in the transmitter. The receiver for the proposed signaling scheme is equipped with the loss compensator to equalize the channel loss caused by the highly resistive signal line-on-glass (LOG) and low channel bandwidth due to open termination on the receiver. The proposed signaling scheme is verified with 9.7-inch XGA (1024RGBx768) resolution TFT-LCD module for tablet computer. The proposed signaling scheme achieves the low electromagnetic near-field radiation from the signal lines by acquiring the good signal integrity on the transmission channel.