12-CHANNEL TRANSMITTER WITH DATA-DEPENDENT JITTER COMPENSATION USING PHASE AND AMPLITUDE EMPHASIS TECHNIQUE

Abstract

In this thesis, a 2.1Gbps 12-channel transmitter using phase emphasis for UHD intra-panel interface is presented. High-speed data must be transmitted from timing controller (TCON) to multiple source drivers (SD) to support high resolution in UHD intra-panel interface. To optimize output signal according to various channel conditions between TCON and SD, each channel driver is designed to control common mode voltage, swing level, and emphasis level of output signal by using PVT insensitive current. Also, the amplitude emphasis and phase emphasis technique are applied to the transmitter to compensate for worst channel with a loss of more than 10dB in the intra-pane interface. The phase emphasis compensates data-dependent-jitter (DDJ) due to the limited bandwidth of the channel by varying the transition start timing according to the data sequence. Therefore, a certain amount of channel loss can be compensated by phase emphasis, which reduces burden on signaling for amplitude emphasis. This paper includes not only the circuit implementation of the phase emphasis scheme but also the mathematical analysis, thus suggesting a method to design and modify the transmitter according to the channel environment to be used. This transmitter is fabricated in 28nm COMS process and its area is 1.35mm2. For a 2.1Gbps PRBS of 27-1 passing through a 10dB loss PCB trace, the measured eye jitter is reduced by 38% by applying the emphasis, and the decrease amount by the phase emphasis reached 50% of the total decrease amount. The proposed transmitter is verified with 55-inch UHD (3840x2160) resolution TFT-LCD intra-panel interface. Our transmitter consumes 12.73mW/Gb/s per channel with 1.2V of output swing level.