Design of High Speed and Precision and Low-Power LVDS Driver for CMOS Image Sensor

Abstract

Aiming at the requirement of high speed and precision, low-power and large-capacity load of serial data interface for aerospace super large array(15k×15k) CMOS image sensor, a design scheme low voltage differential signal (LVDS) driver by combining the split-length method with the pre-emphasis technique is proposed. Firstly, comparing with the general design schemes, the present scheme uses the split-length compensation method to increase effectively the unity-gain bandwidth while keeping the op-amp gain constant. Secondly, the pre-emphasis technique is used to compensate the LVDS driver for high-frequency components to improve the driving capability of the capacitive load and high speed signal integrity (SI). The simulation results show that the accuracy of the common-mode feedback voltage is improved by using the split-length compensation method, and also the common-mode voltage changes below 15 mV. The pre-emphasis technique is used to enhance the amplitude of the high-frequency components lost during the high-speed transmission. The quality of the signal eye diagram during high-speed transmission reduces the bit error rate, and both the transmission rate and the driving load capacity are two times more than the general design (1.2 Gb/s@12 pF), and the quiescent current consumption is only 4.6 mA@12 pF. The present LVDS driver design is implemented in a typical CMOS process of 0.18 μm.

Keywords

• split-length
• lvds
• pre-emphasis
• high speed
• high precision
• low power