A simple and low power capacitive crosstalk compensator

Abstract

Recently, IT devices such as desktops, smart-phones and tablets deal with huge amount of data. To quickly transfer the huge amount of data, interface circuits between transmitter and receiver should operate with high data-rate performance. Even though single-ended parallel interface is a method to achieve the high data-rate, crosstalk noise between the parallel channels is generated. In this thesis, the crosstalk noise compensation is studied. To compensate the crosstalk noise, new approach using capacitive coupling is proposed. The proposed scheme has simple structure, low power consumption, small area, and high jitter reduction. Additionally, a crosstalk adaptation method with low power is studied. A capacitive crosstalk compensator (CXC) at transmitter is presented. It employs double-path capacitive coupling to accurately cancel crosstalk-induced jitter (CIJ). Mode detector and additional clock for compensation are eliminated and only buffers and capacitors are used. The simple architecture consumes low power (1mW/Gbps/CH) and occupies small area (0.009mm2/CH). The chip was fabricated in a 130nm CMOS process. CXC has the maximum jitter reduction with 34.1ps (90.5%) and the maximum voltage improvement with 26.6mV. CXC operates at up to 6.5Gbps. A low power adaptive crosstalk cancellation for single-ended parallel interface is presented. Digital calibration which accurately detects the amount of crosstalk without a reference clock is proposed. To transfer calibration information from a receiver to a transmitter without additional channels, switched termination resistors (STR) are implemented. The proposed techniques achieve low power and small area due to no need for reference clock and the additional channels. A simple crosstalk canceller located at the transmitter requires less design effort and low power. An implemented adaptive 3CH-CXC rapidly determines the optimum calibration point during 4-cycles calibration time, and eliminates crosstalk induced jitte...